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 A345870 #16 Jul 01 2021 12:08:46
%S A345870 1,2,6,26,126,742,5166,40462,351742,3458470,37425406,440788702,
%T A345870 5633316574,77379974518,1140707915262,18053421105742,302414295475134,
%U A345870 5364631473148614,100769601500958078,1988246969908681278,41179474537324087454,896909297854081874454
%N A345870 Expansion of e.g.f. Product_{k>=1} ((1 + x^k)/(1 - x^k))^(1/k!).
%C A345870 Exponential convolution of the sequences A209902 and A298906.
%H A345870 Seiichi Manyama, <a href="/A345870/b345870.txt">Table of n, a(n) for n = 0..449</a>
%F A345870 E.g.f.: exp( 2*Sum_{k>=0} (exp(x^(2*k+1)) - 1)/(2*k+1) ).
%o A345870 (PARI) my(N=40, x='x+O('x^N)); Vec(serlaplace(prod(k=1, N, ((1+x^k)/(1-x^k))^(1/k!))))
%o A345870 (PARI) my(N=40, x='x+O('x^N)); Vec(serlaplace(exp(2*sum(k=0, N\2, (exp(x^(2*k+1))-1)/(2*k+1)))))
%Y A345870 Cf. A005408, A209902, A295792, A298906, A306041, A345871.
%K A345870 nonn
%O A345870 0,2
%A A345870 _Seiichi Manyama_, Jun 27 2021