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 A306156 #23 Apr 13 2025 07:23:42
%S A306156 2,3,2,6,6,11,18,36,56,105,186,346,630,1179,2182,4116,7710,14588,
%T A306156 27594,52482,99858,190743,364722,699216,1342176,2581425,4971008,
%U A306156 9587574,18512790,35792449,69273666,134219796,260300986,505294125,981706806,1908881548,3714566310
%N A306156 Inverse Weigh transform of 2^n.
%H A306156 Seiichi Manyama, <a href="/A306156/b306156.txt">Table of n, a(n) for n = 1..3000</a>
%H A306156 Christian G. Bower, <a href="https://oeis.org/transforms_pari.txt">PARI programs for transforms</a>, 2007.
%H A306156 N. J. A. Sloane, <a href="/transforms.txt">Maple programs for transforms</a>, 2001-2020.
%F A306156 Product_{k>=1} (1+x^k)^a(k) = 1/(1-2x).
%F A306156 a(n) = (1/n) * (2^n + Sum_{d<n and d|n} (-1)^(n/d) * d * a(d)).
%e A306156 (1+x)^2*(1+x^2)^3*(1+x^3)^2*(1+x^4)^6* ... = 1 + 2*x + 4*x^2 + 8*x^3 + 16*x^4 + ... .
%Y A306156 Inverse Weigh transform of b^n: this sequence (b=2), A306157 (b=3), A306158 (b=4), A306159 (b=5).
%Y A306156 Cf. A000079, A038067, A102866.
%K A306156 nonn
%O A306156 1,1
%A A306156 _Seiichi Manyama_, Jun 23 2018