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 A274294 a(n) = 1+(n+1)^2+n!+Sum_{k=1..n-1} binomial(n,k)*n!/(n-k)!. 1
 3, 6, 16, 50, 234, 1582, 13376, 130986, 1441810, 17572214, 234662352, 3405357826, 53334454586, 896324308830, 16083557845504, 306827170866362, 6199668952527906, 132240988644216166, 2968971263911289360, 69974827707903049554, 1727194482044146637962 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 COMMENTS Number of residuated maps on the lattice M_n. LINKS Erika D. Foreman, Order automorphisms on the lattice of residuated maps of some special nondistributive lattices, (2015). Univ. Louisville, Electronic Theses and Dissertations. Paper 2257. FORMULA a(n) = (n+1)^2 +n! + A070779(n-1), n>=1. - R. J. Mathar, Jul 16 2020 MAPLE f:=n->1+(n+1)^2+n!+add(binomial(n, k)*n!/(n-k)!, k=1..n-1); [seq(f(n), n=0..20)]; CROSSREFS Cf. A317094. Sequence in context: A007002 A305136 A300355 * A201969 A340498 A288850 Adjacent sequences:  A274291 A274292 A274293 * A274295 A274296 A274297 KEYWORD nonn AUTHOR N. J. A. Sloane, Jun 18 2016 STATUS approved

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Last modified June 24 20:20 EDT 2021. Contains 345425 sequences. (Running on oeis4.)