This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A023874 #41 Sep 08 2022 08:44:47 %S A023874 1,1,33,276,1828,12729,88903,582846,3690325,22864592,138658796, %T A023874 822374485,4781447342,27314310586,153519181630,849786024496, %U A023874 4637270263913,24970548655999,132788838463944,697863705334941,3626864249759775,18650694625385462,94948991121030892 %N A023874 Expansion of Product_{k>=1} (1 - x^k)^(-k^5). %H A023874 Seiichi Manyama, <a href="/A023874/b023874.txt">Table of n, a(n) for n = 0..2338</a> (first 601 terms from Alois P. Heinz) %H A023874 G. Almkvist, <a href="http://www.emis.de/journals/EM/expmath/volumes/7/7.html">Asymptotic formulas and generalized Dedekind sums</a>, Exper. Math., 7 (No. 4, 1998), pp. 343-359. %H A023874 Vaclav Kotesovec, <a href="http://arxiv.org/abs/1509.08708">A method of finding the asymptotics of q-series based on the convolution of generating functions</a>, arXiv:1509.08708 [math.CO], Sep 30 2015, p. 21. %F A023874 a(n) ~ 3^(127/882) * (5*Zeta(7))^(127/1764) * exp(7 * n^(6/7) * (5*Zeta(7))^(1/7) / (2^(3/7) * 3^(5/7)) + Zeta'(-5)) / (2^(187/882) * n^(1009/1764) * sqrt(7*Pi)), where Zeta(7) = A013665 = 1.008349277381922826..., Zeta'(-5) = ((137/60 - gamma - log(2*Pi))/42 + 45*Zeta'(6) / (2*Pi^6))/6 = -0.0005729859801986352... . - _Vaclav Kotesovec_, Feb 27 2015 %F A023874 G.f.: exp( Sum_{n>=1} sigma_6(n)*x^n/n ). - _Seiichi Manyama_, Mar 05 2017 %F A023874 a(n) = (1/n)*Sum_{k=1..n} sigma_6(k)*a(n-k). - _Seiichi Manyama_, Mar 05 2017 %p A023874 with(numtheory): %p A023874 a:= proc(n) option remember; `if`(n=0, 1, %p A023874 add(add(d*d^5, d=divisors(j)) *a(n-j), j=1..n)/n) %p A023874 end: %p A023874 seq(a(n), n=0..25); # _Alois P. Heinz_, Nov 02 2012 %t A023874 max = 22; Series[ Product[1/(1 - x^k)^k^5, {k, 1, max}], {x, 0, max}] // CoefficientList[#, x] & (* _Jean-François Alcover_, Mar 05 2013 *) %o A023874 (PARI) m=30; x='x+O('x^m); Vec(prod(k=1, m, 1/(1-x^k)^k^5)) \\ _G. C. Greubel_, Oct 30 2018 %o A023874 (Magma) m:=30; R<x>:=PowerSeriesRing(Rationals(), m); Coefficients(R! ( (&*[1/(1-x^k)^k^5: k in [1..m]]) )); // _G. C. Greubel_, Oct 30 2018 %Y A023874 Column k=5 of A144048. %K A023874 nonn %O A023874 0,3 %A A023874 _Olivier Gérard_ %E A023874 Definition corrected by _Franklin T. Adams-Watters_ and _R. J. Mathar_, Dec 04 2006