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 A345040 #7 Jun 07 2021 06:51:35
%S A345040 1,2,3,12,268,25853,19339964,68901690994,1638901380861357,
%T A345040 363916628499805466764,384738112277336112497203088,
%U A345040 4821999492342155731355029409443825,448660704121129122524211570743600451959266,270068948293205668896252888517768674319536620944042
%N A345040 a(n) = Sum_{k=0..n} Stirling2(n,k)^k.
%t A345040 Unprotect[Power]; 0^0 = 1; Table[Sum[StirlingS2[n, k]^k, {k, 0, n}], {n, 0, 13}]
%o A345040 (PARI) a(n) = sum(k=0, n, stirling(n, k, 2)^k) \\ _Felix Fröhlich_, Jun 06 2021
%Y A345040 Cf. A000110, A008277, A047797, A048993, A167008, A345041.
%K A345040 nonn
%O A345040 0,2
%A A345040 _Ilya Gutkovskiy_, Jun 06 2021