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 A226855 #17 Sep 08 2022 08:46:05
%S A226855 0,1,4,12,44,175,762,3605,18384,100404,584070,3601895,23451540,
%T A226855 160633681,1153896772,8668821600,67943174000,554327140739,
%U A226855 4698491153454,41299244789989,375844030441560
%N A226855 a(n) = n*B(n-1) + n*(n-1)*B(n-2), where the B(i) are Bell numbers (A000110).
%H A226855 Vincenzo Librandi, <a href="/A226855/b226855.txt">Table of n, a(n) for n = 0..200</a>
%H A226855 B. Chern, P. Diaconis, D. M. Kane, R. C. Rhoades, <a href="http://math.stanford.edu/~rhoades/FILES/setpartitions.pdf">Closed expressions for averages of set partition statistics</a>, 2013.
%t A226855 Table[n BellB[n-1] + n (n-1) BellB[n-2], {n, 0, 30}] (* _Vincenzo Librandi_, Jul 16 2013 *)
%o A226855 (PARI) B(n) = if (n<=1, return (1), return (sum(i=0, n-1, binomial(n-1, i)*B(n-1-i))))
%o A226855 a(n) = n*B(n-1) + n*(n-1)*B(n-2)
%o A226855 (Magma) [0,1] cat [n*Bell(n-1)+n*(n-1)*Bell(n-2): n in [2..25]]; // _Vincenzo Librandi_, Jul 16 2013
%Y A226855 Cf. A052889 (see Prop 3.1 (ii) in Chern et al. link).
%K A226855 nonn
%O A226855 0,3
%A A226855 _Michel Marcus_, Jun 19 2013