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 A371309 #23 Mar 24 2024 08:13:15
%S A371309 1,1,4,21,88,645,4386,33061,296808,2674377,26757190,285294801,
%T A371309 3199971336,38104015417,476816609192,6261875218215,85736036949856,
%U A371309 1227373767823617,18255004438680558,281702101344334993,4509097743074878200,74606738071821274641,1275212550939684334384
%N A371309 Expansion of e.g.f. Product_{k>=1} (1 + x^k/k!)^(k^2).
%C A371309 "EGJ" (unordered, element, labeled) transform of squares.
%H A371309 C. G. Bower, <a href="/transforms2.html">Transforms (2)</a>
%t A371309 nmax = 22; CoefficientList[Series[Product[(1 + x^k/k!)^(k^2), {k, 1, nmax}], {x, 0, nmax}], x] Range[0, nmax]!
%Y A371309 Cf. A000290, A007837, A027998, A032315, A032316.
%K A371309 nonn
%O A371309 0,3
%A A371309 _Ilya Gutkovskiy_, Mar 24 2024