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 A359733 #16 Aug 14 2023 02:00:21
%S A359733 1,4,7,20,21,88,71,296,373,1084,1035,5084,4109,16496,20787,67728,
%T A359733 65553,286516,262163,1070180,1189937,4194568,4194327,17760824,
%U A359733 16827241,67109228,72150655,269503660,268435485,1104603808,1073741855,4303389216,4476371181
%N A359733 a(n) = (1/2) * Sum_{d|n} (2*d)^(n/d).
%F A359733 G.f.: Sum_{k>0} k * x^k / (1 - 2 * k* x^k).
%t A359733 a[n_] := DivisorSum[n, (2*#)^(n/#) &] / 2; Array[a, 33] (* _Amiram Eldar_, Aug 14 2023 *)
%o A359733 (PARI) a(n) = sumdiv(n, d, (2*d)^(n/d))/2;
%o A359733 (PARI) my(N=40, x='x+O('x^N)); Vec(sum(k=1, N, k*x^k/(1-2*k*x^k)))
%Y A359733 Cf. A055225, A076717.
%K A359733 nonn,easy
%O A359733 1,2
%A A359733 _Seiichi Manyama_, Jan 12 2023