Recent problems by Ovidiu Furdui

1. Proposed problem to Mathematics Magazine, in press, pdf

2. Proposed problem to Crux Mathematicorum with Mathematical Mayhem, Published, Vol. 34, February 2008, pdf

3. Proposed problem to Mathematics Magazine, in press, pdf

4. Proposed problem to Crux Mathematicorum with Mathematical Mayhem, Published as Problem 3357, September 2008, pdf

5. Proposed problem to La Gaceta de la RSME, Published, pdf

6. Proposed problem to The College Mathematics Journal, Published, pdf

7. Proposed problem to The Fibonacci Quarterly, Published, pdf

8. Proposed problem to Crux with Mayhem, in press, pdf

9. O formula trigonometrica, A trigonometric identity, pdf

10. Proposed problem to Mathematical Magazine, in press, pdf

11. Proposed problem to La Gaceta de la RSME, Published, pdf

12. A quadratic exponential sum, pdf

13. Proposed problem to Mathematical Reflections, in press, pdf

14. Proposed problem to Publ.Elek.Fak., in press, pdf

15. Proposed problem to PME Journal, Published, pdf

16. Proposed problem to Math Horizon, in press, pdf

17. Proposed problem to Mathematical Reflections, in press, pdf

18. Proposed problem to Elemente der Mathematik, in press, pdf

19. Proposed problem to The American Mathematical Monthly, in press, pdf

20. Proposed problem to La Gaceta de la RSME, Published, pdf

21. Proposed problem to REOIM, Published, pdf

22. Proposed problem, The College Mathematics Journal, Published as Problem 877, May 2008, pdf

23. A series representation of the Catalan constant, pdf

24. Proposed problem, MJMS, A Leibniz series, Published, pdf

25. Two series representations of the Glaisher-Kinkelin constant, pdf

26. Proposed problem, Mathematics Magazine, Problem 1784, Mathematics Magazine, Vol.80, December 2007, pdf

27. The limit of a product, pdf

28. Another Leibniz Series, Published, pdf

29. Proposed problem, The American Mathematical Monthly, Published, pdf

30. Proposed problem, The American Mathematical Monthly, Published, pdf

31. A Ramanujan-like-formula, AADM, in press, pdf

32. Proposed problem, Crux with Mayhem, A Zeta limit, in press, pdf

33. Proposed problem, Mathematics Magazine, A Double Improper Integral, in press, pdf

34. Proposed problem, The Mathematical Gazette, An Improper Integral, To appear, pdf

35. Proposed problem, Siam Problems and Solutions, in press, pdf

36. A generalization of a Dostanic-Zhu lemma, pdf

37. Proposed problem, Math Horizon, An alternating series, in press, pdf

38. A sequence of rational numbers, pdf

39. Proposed problem, Revista Escolar, A Riemann integral, Published, pdf

40. An integral, pdf

41. Proposed problem, La Gaceta de la RSME, A multiple harmonic series, in press, pdf

42. Proposed problem, Crux with Mayhem, A geometry problem, in press, pdf

43. Proposed problem, Revista Escolar, A double fractional integral, Published, pdf

44. Proposed problem, Siam Problems and Solutions, Published, pdf

45. Proposed problem, Niew Archief Voor Wiskunde, To appear, pdf

46. Proposed problem, Mathematics Magazine, in press, pdf

47. Two log limits, pdf

48. A simple limit, pdf

49. The limit of an integral, pdf

50. New, A conjecture in solid geometry***, An interior point characterization of regular tetrahedra, Crux with mayhem, in press, pdf

51. New ***,  Proposed problem, The limit of two $n^{th}$ roots, The American Mathematical Monthly, Published, Vol. 115, January 2008, pdf

52. New **, Proposed problem, Mathematics Magazine, A convergence criteria for improper integrals, To appear, October 2008, pdf

53. New ***, Proposed Problem, Nieuw Archief Voor Wiskunde, pdf

54. New **, Proposed Problem, A Riemann Zeta Series, Siam Problems and Solutions, Submitted, pdf

55. New****, Proposed Problem, La Gaceta de la RSME, Published, Vol. 11, Number 1, 2008, pdf , pdf

56. New, Proposed Problem, PME Journal, To appear, Problem 1172, Spring 2008, pdf

57. New, Proposed Problem, Nieuw Archief Voor Wiskunde, A logarithmic series, Submitted, pdf

58. New, Proposed Problem, School Science and Mathematics, A logarithmic integral, Published, pdf

59. New, A quickie, pdf

60. New **, Proposed Problem, La Gaceta de la RSME, A criteria for convergence of some exponential integrals, pdf

61. New, Proposed Problem, PME Journal, submitted, pdf

62. New, Proposed Problem, pdf

63. New***, Proposed Problem, The Harvard College Mathematics Review, A tricky limit, Published, pdf

64. New, Proposed Problem, CMJ, Two Logarithmic Series, Published, Vol. 39, No.2, March 2008, pdf

65. New**, Proposed Problem, Mathematics Magazine, The Limit of Three Square Roots, Published , pdf

66. New, Proposed Problem, Revista Escolar, Published, Problema 155, Numero 31, 2008, pdf

67. New, Proposed Problem, Revista Escolar, Submitted, pdf

68. New, Proposed Problem, School Science and Mathematics, Published, pdf

69. 10 ale lunii Noiembrie, 2007, November 10, 2007, New ***, Two Riemann Zeta Limits, pdf

70. 10 ale lunii Noiembrie, 2007, November 10, 2007, Problem A, Nieuw Archief voor Wiskunde, 5/9, Maart 2008, pdf

71. 12 ale lunii Noiembrie, 2007, November 12, 2007, New, Proposed Problem, Mathematics Magazine, A "quick" diophantine equation, To appear , April 2008, Q980, pdf

72. 12 ale lunii Noiembrie, 2007, November 12, 2007, New, A "quick" fractional integral, pdf

73. 15 ale lunii Noiembrie, 2007, November 15, 2007, New, Proposed Problem, MJMS, To appear, pdf

74. 30 ale lunii Noiembrie, 2007, November 30, 2007, New, A Stirling type formula for the n^{th} root of the product of the binomial coefficients, The Mathematical Gazette, To appear, pdf
75. 5 ale lunii Decembrie, 2007, December 5, 2007, New***, The Convergence of Two Multiple Series pdf

76. 7 ale lunii Decembrie, 2007, December 7, 2007, New***, Proposed Problem, AADM, A Conjecture, The diedral angle characterization of regular tetrahedra, pdf

77. 13 ale lunii Decembrie, 2007, December 13, 2007, New, To appear, The American Mathematical Monthly, pdf

78. 28 ale lunii Decembrie, 2007, December 28, 2007, School Science and Mathematics, pdf, Published as Problem 5013, Vol. 103, March, 2008, pdf

2008

79. 2 Ianuarie, 2008, January 2, 2008, Proposed Problem, Some Cosine Integral Series , SIAM, Published, pdf

80. 3 Ianuarie, 2008, January 3, 2008, Proposed Problem, A Multiple Alternating Series , Crux Mathematicorum with Mathematical Mayhem, Submitted, pdf

81. 9 Ianuarie, 2008, January 9, 2008, Proposed Problem, A Curious Product , The American Mathematical Monthly, Published pdf

82. 14 Ianuarie, 2008, January 14, 2008, Proposed Problem, The Mathematical Gazette, To appear, pdf

83. 1 Februarie, 2008, February 1, 2008, Proposed Problem, La Gaceta de la RSME, Published as Problema 103, Vol. 11, No.2, 2008, pdf

84. 4 Februarie, 2008, February 4, 2008, A Diophantine Equation, Published in The Harvard College Mathematics Review, Vol.2, No.1, Spring 2008, pdf

6 Mai, 2008, May 6, 2008, An Interesting Generalization, pdf

85. 15 Februarie, 2008, February 15, 2008, Proposed Problem, Crux Mathematicorum with Mathematical Mayhem, pdf

86. 27 Februarie, 2008, February 27, 2008, Proposed Problem, The Mathematical Gazette, To appear, November 2008, pdf

87. 1 Martie, 2008, March 1, 2008, Proposed Problem, Crux Mathematicorum with Mathematical Mayhem, Submitted, pdf

88. 11 Martie, 2008, March 11, 2008, Proposed Problem, La Gaceta de la RSME, A class of double integrals, Published, pdf

89***. 8 Aprilie, 2008, April 8, 2008, Proposed Problem, The American Mathematical Monthly, Submitted, pdf

90. 12 Aprilie, 2008, April 12, 2008, Proposed Problem, La Gaceta de la RSME, An alternating series with gaps, pdf

91. 14 Aprilie, 2008, April 14, 2008, Proposed Problem, Crux Mathematicorum with Mathematical Mayhem, A Taylorian alternating series, pdf

92. 5 Mai, 2008, May 5, 2008, Summing Some Zeta Series, pdf

93. 7 Mai, 2008, May 7, 2008, Proposed Problem, Elemente der Mathematik, Accepted for publication, pdf

94. 8 Mai, 2008, May 8, 2008, A Stirling Type Product-An Unexpected Result, pdf

Probleme pentru vacanta de vara 2008

95. 13 Mai, 2008, May 13, 2008, A Glaisher Kinkelin Product, , To appear, pdf

96. 23 Mai, 2008, May 23, 2008, Proposed Problem, Mathematical Reflections, Published as Problem U 95 pdf

97. 17 Mai, 2008, May 17, 2008, Proposed Problem, Revista Escolar, pdf, Some generalizations, pdf

98. 26 Mai, 2008, May 26, 2008, Proposed Problem, Revista Escolar, Published as Problema 157, pdf

99. 27 Mai, 2008, May 27, 2008, Proposed Problem, The College Mathematics Journal, Accepted for publication, pdf

Semestrul de toamna 2008

100. 27 August, 2008, August 27, 2008, A Multiple Limit, pdf

101. 2 Septembrie, 2008, September 2, 2008, Proposed Problem to Crux with Mayhem, pdf

102. New, Proposed Problem, The American Mathematical Monthly, pdf

Another problem on a related topic, pdf

An exponential limit, pdf

103. A double integral of a logarithmic gamma function, Accepted for publication, pdf

104. An integral, a limit and a geometric mean, pdf

105. Proposed Problem , Crux Mathematicorum with Mathematical Mayhem, pdf

106. Proposed Problem, School Science and Mathematics, pdf

107. Proposed Problem, Siam Problems and Solutions , pdf

108. Proposed Problem, Crux with Mayhem, pdf

109. Proposed Problem, La Gaceta de la RSME, pdf

Limits of quadratic type sequences, pdf

110. Proposed Problem, The College Mathematics Journal, To Appear, pdf

111. Proposed Problem, Crux Mathematicorum with Mathematical Mayhem, Submitted, pdf

112. Proposed Problem, Crux Mathematicorum with Mathematical Mayhem, Submitted, pdf

113. Proposed Problem, Mathematics Magazine, A Double Alternating Series, pdf

114. Proposed Problem, SSM, A Simple Alternating Series, pdf

 

Limits, Integrals and Series

1. A Gamma Function limit, pdf

2. A curious limit, pdf

3. An alternanting sum, pdf

4. 7 Ianuarie, 2008, January 7, 2008, Three Logarithmic Series , pdf

5. 18 Ianuarie, 2008, January 18, 2008, O Limita Frumoasa , pdf

6. 29 Februarie, 2008, February 18, 2008, A Multiple Integral, pdf

7. 14 Aprilie, 2008, April 14, 2008, Some Classes of Taylorian Alternating Series, pdf

8. 10 Mai, 2008, May 14, 2008, The Convergence of some Lalescu series, pdf

 

Gems, Mathematical Techniques, Intriguing Results

1. An integral formula, pdf

2. A Convergence Criteria, The Brazilian problem,  pdf

3. Some "Exponential" limits, pdf

4. An interesting sequence, pdf

5. Some tauberian limits, pdf

6. A nice sum, pdf

7. 7 Aprilie, 2008, April 7, 2008, Holder's inequality implies AM-GM inequality, pdf

 

Quickies

1. A Quick Harmonic Sum, A problem from Ungheria, pdf

 

Open Problems

1. Some improper integrals, pdf

2. A multiple Riemann integral, pdf

3. The limit of a difference of two n^{th} roots of Gamma functions, pdf

4. Some alternating series, pdf

5. 22 ale lunii Noiembrie, 2007, November 22, 2007, A double alternating series, New, pdf

6. 23 ale lunii Noiembrie, 2007, November 23, 2007, A difficult double series, New, pdf

7. 25 ale lunii Noiembrie, 2007, November 25, 2007, A multiple series, New, pdf

8. 28 ale lunii Decembrie, 2007, December 28, 2007, An alternating series involving Gamma and Gamma, New, pdf

9. 25 ale lunii Noiembrie, 2007, November 25, 2007, The asymptotic behavior of two sequences, (Not yet posted).

10. 1 Ianuarie, 2008, January 1, 2008, An alternating series involving Zeta function, pdf

11. 23 Februarie, 2008, February 23, 2008, A fractional integral and its generalization, pdf

12. 25 Februarie, 2008, February 25, 2008, A multiple fractional integral, pdf

13. 25 Februarie, 2008, February 25, 2008, When two generalized harmonic numbers are divisible?, (Not yet posted). pdf