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 A192546 #8 Dec 15 2023 14:35:58
%S A192546 1,1,4,26,251,3157,50310,978315,22616102,610543614,18953178234,
%T A192546 668200802513,26484030901784,1169889631517219,57168091338306720,
%U A192546 3070545537985858612,180251920018830890897,11507450028966272232867,795397552661209049095698
%N A192546 a(n) = sum(stirling2(n,k)*stirling2(n+1,k+1),k=0..n).
%H A192546 Vincenzo Librandi, <a href="/A192546/b192546.txt">Table of n, a(n) for n = 0..52</a>
%t A192546 Table[Sum[StirlingS2[n,k]StirlingS2[n+1,k+1],{k,0,n}],{n,0,100}]
%t A192546 Total/@Table[StirlingS2[n,k]StirlingS2[n+1,k+1],{n,0,20},{k,0,n}] (* _Harvey P. Dale_, Dec 15 2023 *)
%o A192546 (Maxima) makelist(sum(stirling2(n,k)*stirling2(n+1,k+1),k,0,n),n,0,24);
%Y A192546 Cf. A047793
%K A192546 nonn
%O A192546 0,3
%A A192546 _Emanuele Munarini_, Jul 04 2011