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 A306159 #21 Apr 13 2025 07:24:37
%S A306159 5,15,40,165,624,2620,11160,48915,217000,976872,4438920,20346320,
%T A306159 93900240,435970980,2034504992,9536767665,44878791360,211927733500,
%U A306159 1003867701480,4768372070592,22706531339280,108372083629260,518301258916440,2483526875798820
%N A306159 Inverse Weigh transform of 5^n.
%H A306159 Seiichi Manyama, <a href="/A306159/b306159.txt">Table of n, a(n) for n = 1..1000</a>
%H A306159 Christian G. Bower, <a href="https://oeis.org/transforms_pari.txt">PARI programs for transforms</a>, 2007.
%H A306159 N. J. A. Sloane, <a href="/transforms.txt">Maple programs for transforms</a>, 2001-2020.
%F A306159 Product_{k>=1} (1+x^k)^a(k) = 1/(1-5x).
%F A306159 a(n) = (1/n) * (5^n + Sum_{d<n and d|n} (-1)^(n/d) * d * a(d)).
%e A306159 (1+x)^5*(1+x^2)^15*(1+x^3)^40*(1+x^4)^165* ... = 1 + 5*x + 25*x^2 + 125*x^3 + 625*x^4 + ... .
%Y A306159 Inverse Weigh transform of b^n: A306156 (b=2), A306157 (b=3), A306158 (b=4), this sequence (b=5).
%Y A306159 Cf. A000351, A038070.
%K A306159 nonn
%O A306159 1,1
%A A306159 _Seiichi Manyama_, Jun 23 2018