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 A069471 #9 Nov 16 2021 07:15:39
%S A069471 1,1,5,38,404,5640,98769,2099606,52883390,1549218221,52014755913,
%T A069471 1977659061064,84305075757125,3995485979209678,209005906088572893,
%U A069471 11992147240091361387,750583356339067110013,50998365413706734478011
%N A069471 Stirling transform of squares of Bell numbers: a(0)=1, a(n) = Sum_{k=1..n} Stirling2(n,k)*(bell(k))^2.
%H A069471 G. C. Greubel, <a href="/A069471/b069471.txt">Table of n, a(n) for n = 0..250</a>
%t A069471 Join[{1}, Table[Sum[StirlingS2[n, k]*BellB[k]^2, {k, 1, n}], {n, 1, 50}]] (* _G. C. Greubel_, May 23 2018 *)
%Y A069471 Cf. A000110, A001247, A008277.
%K A069471 nonn
%O A069471 0,3
%A A069471 _Karol A. Penson_, Mar 25 2002