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 A158265 #5 Oct 31 2024 11:32:53
%S A158265 1,2,11,74,697,8002,115158,1949640,38662510,872245634,22150393253,
%T A158265 623661939852,19296665400632,650198159192554,23700604926216759,
%U A158265 928939297013294294,38956230043045053042,1740248411222193973416
%N A158265 G.f.: A(x) = exp( Sum_{n>=1} 2*sigma(n,n+1)*x^n/n ).
%C A158265 Definition: sigma(n,n+1) = Sum_{d|n} d^(n+1): [1,9,82,1057,15626,...].
%F A158265 a(n) ~ 2 * exp(1) * n^(n-1). - _Vaclav Kotesovec_, Oct 31 2024
%e A158265 G.f.: A(x) = 1 + 2*x + 11*x^2 + 74*x^3 + 697*x^4 + 8002*x^5 +...
%e A158265 log(A(x)) = 2*x + 18*x^2/2 + 164*x^3/3 + 2114*x^4/4 + 31252*x^5/5 +...
%o A158265 (PARI) a(n)=polcoeff(exp(sum(m=1, n, 2*sigma(m, m+1)*x^m/m)+x*O(x^n)), n)
%Y A158265 Cf. A158095, A023881, A082245.
%K A158265 nonn
%O A158265 0,2
%A A158265 _Paul D. Hanna_, Mar 29 2009