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 A274294 #17 Feb 17 2023 15:22:07
%S A274294 3,6,16,50,234,1582,13376,130986,1441810,17572214,234662352,
%T A274294 3405357826,53334454586,896324308830,16083557845504,306827170866362,
%U A274294 6199668952527906,132240988644216166,2968971263911289360,69974827707903049554,1727194482044146637962
%N A274294 a(n) = 1+(n+1)^2+n!+Sum_{k=1..n-1} binomial(n,k)*n!/(n-k)!.
%C A274294 Number of residuated maps on the lattice M_n.
%H A274294 Erika D. Foreman, <a href="http://dx.doi.org/10.18297/etd/2257">Order automorphisms on the lattice of residuated maps of some special nondistributive lattices</a>, (2015). Univ. Louisville, Electronic Theses and Dissertations. Paper 2257.
%F A274294 a(n) = (n+1)^2 +n! + A070779(n-1), n>=1. - _R. J. Mathar_, Jul 16 2020
%p A274294 f:=n->1+(n+1)^2+n!+add(binomial(n,k)*n!/(n-k)!,k=1..n-1);
%p A274294 [seq(f(n),n=0..20)];
%t A274294 Table[1+(n+1)^2+n!+Sum[Binomial[n,k] n!/(n-k)!,{k,n-1}],{n,0,20}] (* _Harvey P. Dale_, Feb 17 2023 *)
%Y A274294 Cf. A317094.
%K A274294 nonn
%O A274294 0,1
%A A274294 _N. J. A. Sloane_, Jun 18 2016