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 A329256 #14 May 01 2022 06:02:24 %S A329256 1,1,1,1,2,6,16,36,106,443,1796,6161,23816,122266,643644,2934296, %T A329256 14002237,83835433,532282819,3005258539,17039094646,115611682810, %U A329256 848428608644,5682350940168,37297365940462,281594230420802,2323660209441962,17929392395804072 %N A329256 Expansion of e.g.f. exp(Sum_{k>=1} x^(k^2) / (k^2)!). %H A329256 Seiichi Manyama, <a href="/A329256/b329256.txt">Table of n, a(n) for n = 0..611</a> %F A329256 a(0) = 1; a(n) = Sum_{k=1..n} binomial(n-1,k-1) * A010052(k) * a(n-k). %t A329256 nmax = 27; CoefficientList[Series[Exp[Sum[x^(k^2)/(k^2)!, {k, 1, Floor[nmax^(1/2)] + 1}]], {x, 0, nmax}], x] Range[0, nmax]! %t A329256 a[n_] := a[n] = Sum[Binomial[n - 1, k - 1] Boole[IntegerQ[k^(1/2)]] a[n - k], {k, 1, n}]; a[0] = 1; Table[a[n], {n, 0, 27}] %o A329256 (PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(exp(sum(k=1, sqrtint(N), x^k^2/(k^2)!)))) \\ _Seiichi Manyama_, Apr 29 2022 %o A329256 (PARI) a(n) = if(n==0, 1, sum(k=1, sqrtint(n), binomial(n-1, k^2-1)*a(n-k^2))); \\ _Seiichi Manyama_, Apr 29 2022 %Y A329256 Cf. A000110, A010052, A205799, A205800, A205801, A205802, A205804, A353180. %K A329256 nonn %O A329256 0,5 %A A329256 _Ilya Gutkovskiy_, Nov 09 2019