Search: id:A105639 Results 1-1 of 1 results found. %I A105639 %S A105639 0,1,3,51,2635,321315,79244571,35534634163,26790753983211,31980883597248195, %T A105639 57639013468037578555,150903079070698932214611,555841597474333410204232203, %U A105639 2804056152239296833617706906211,18933384891214439885244043983467355 %N A105639 Multiples of coefficients in an asymptotic series of Ramanujan. %D A105639 G. H. Hardy, Srinivasa Ramanujan (1887-1920), pp. xxi-xxxvi of Collected Papers of Srinivasa Ramanujan, Ed. G. H. Hardy et al., AMS Chelsea 2000. See page xxvi VII. (4) %F A105639 a(n)=-G(n)G(n+1) where G=A001469 Genocchi numbers. %F A105639 Sum_{k>0} k^2/(e^(kx)-1) = zeta(3)2/x^3 -1/(12x) + Sum_{k>0} a(k)x^(2k-1)/ ((2k)!(2k+2)4(2^(2k)-1)(2^(2k+2)-1)). %e A105639 x/1440 +x^3/181440 +x^5/7257600 +x^7/159667200 +691x^9/1569209241600 +... %o A105639 (PARI) a(n)=if(n<0,0, n*=2; -4*(2^n-1)*(4*2^n-1)*bernfrac(n)*bernfrac(n+2)) %Y A105639 Cf. A001469. %Y A105639 Sequence in context: A145242 A075869 A126685 this_sequence A003028 A069343 A084882 %Y A105639 Adjacent sequences: A105636 A105637 A105638 this_sequence A105640 A105641 A105642 %K A105639 nonn %O A105639 0,3 %A A105639 Michael Somos, Apr 16 2005 Search completed in 0.004 seconds