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 A339401 #32 May 27 2022 15:35:05
%S A339401 1,1,3,19,63,322,44683,941977,4677605,668520163,21622993111,
%T A339401 9759873853,31135480907413,194137920764803,64440211018897379,
%U A339401 3298807094967155971,181322497435007616497,532556590750629416219,665881649529214120845679,2596711638295426703997397,1031081559092352146579024047
%N A339401 a(n) = numerator of (1/e)^n * Sum_{k>=0}(n^k*k^n)/(n!*k!).
%F A339401 a(n)/A339402(n) = A242817(n)/n!. - _Pontus von Brömssen_, Dec 03 2020
%F A339401 a(n) = numerator([x^n] exp(n*(exp(x)-1))). - _Alois P. Heinz_, Dec 07 2020
%p A339401 A:= proc(n, k) option remember; `if`(n=0, 1, (1+
%p A339401 add(binomial(n-1, j-1)*A(n-j, k), j=1..n-1))*k)
%p A339401 end:
%p A339401 a:= n-> numer(A(n$2)/n!):
%p A339401 seq(a(n), n=0..20); # _Alois P. Heinz_, Dec 07 2020
%t A339401 a[n_] := BellB[n, n]/n! // Numerator;
%t A339401 Table[a[n], {n, 0, 20}] (* _Jean-François Alcover_, May 27 2022 *)
%Y A339401 Cf. A242817, A339402 (denominators).
%K A339401 nonn,frac
%O A339401 0,3
%A A339401 _William C. Laursen_, Dec 03 2020