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 A359732 #15 Aug 14 2023 02:00:25
%S A359732 1,9,244,16393,1953126,362797308,96889010408,35184372105225,
%T A359732 16677181699666813,10000000000001953134,7400249944258160101212,
%U A359732 6624737266949237373933820,7056410014866816666030739694,8819763977946281130541873428720
%N A359732 a(n) = Sum_{d|n} d^(2*d-1).
%F A359732 G.f.: Sum_{k>0} k^(2*k-1) * x^k / (1 - x^k).
%t A359732 a[n_] := DivisorSum[n, #^(2*# - 1) &]; Array[a, 15] (* _Amiram Eldar_, Aug 14 2023 *)
%o A359732 (PARI) a(n) = sumdiv(n, d, d^(2*d-1));
%o A359732 (PARI) my(N=20, x='x+O('x^N)); Vec(sum(k=1, N, k^(2*k-1)*x^k/(1-x^k)))
%Y A359732 Cf. A308688, A308696, A359731.
%K A359732 nonn,easy
%O A359732 1,2
%A A359732 _Seiichi Manyama_, Jan 12 2023