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 A360755 #15 Aug 02 2023 02:00:34
%S A360755 1,3,4,12,16,46,64,160,268,592,1024,2292,4096,8640,16544,33824,65536,
%T A360755 133856,262144,529576,1049920,2108416,4194304,8417408,16777296,
%U A360755 33607680,67118080,134334656,268435456,537140208,1073741824,2148015104,4295023616,8591048704
%N A360755 Expansion of (1/2) * Sum_{k>0} (2 * x * (1 + x^k))^k.
%F A360755 a(n) = Sum_{d|n} 2^(d-1) * binomial(d,n/d-1).
%F A360755 If p is an odd prime, a(p) = 2^(p-1).
%t A360755 a[n_] := DivisorSum[n, 2^(#-1) * Binomial[#, n/# - 1] &]; Array[a, 35] (* _Amiram Eldar_, Aug 02 2023 *)
%o A360755 (PARI) my(N=40, x='x+O('x^N)); Vec(sum(k=1, N, (2*x*(1+x^k))^k)/2)
%o A360755 (PARI) a(n) = sumdiv(n, d, 2^(d-1)*binomial(d, n/d-1));
%Y A360755 Cf. A360726, A360756.
%K A360755 nonn
%O A360755 1,2
%A A360755 _Seiichi Manyama_, Feb 19 2023