# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a006956 Showing 1-1 of 1 %I A006956 M2211 #18 May 08 2018 15:11:54 %S A006956 1,1,1,1,3,1,1,15,1,5,21,5,1,21,1,1,231,5,1,1365,1,55,21,1,1,663,11,5, %T A006956 57,5,1,15015,1,17,483,1,11,25935,1,5,21,935,1,7917,1,23,19437,5,1, %U A006956 3315,1,55,21,1,1,191919,253,2465,21,5,1,1734915,1,1,17157,17,1 %N A006956 Denominator of (2n+1)(2n+2) B_{2n}, where B_n are the Bernoulli numbers. Also denominators of the asymptotic expansion of the polygamma function psi'''(z). %D A006956 M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, Tenth Printing, 1972, p. 260, (6.4.14). %D A006956 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %H A006956 Vincenzo Librandi, Table of n, a(n) for n = 3..1000 %H A006956 M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards, Applied Math. Series 55, Tenth Printing, 1972 [alternative scanned copy]. %H A006956 M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, Tenth Printing, 1972, p. 260, (6.4.14). %t A006956 Join[{1, 1}, Table[Denominator[(4 n^2 + 6 n + 2) BernoulliB[2 n]], {n, 1, 70}]] (* _Vincenzo Librandi_, Aug 02 2013 *) %Y A006956 Numerators are in A076549. Cf. A006955/A002427. %K A006956 nonn,frac %O A006956 3,5 %A A006956 _Simon Plouffe_ %E A006956 More terms from _Ralf Stephan_, Oct 19 2002 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE