A129255 Permutations with exactly 12 fixed points.
1, 0, 91, 910, 16380, 272272, 4919460, 93419352, 1868513010, 39238479280, 863247190806, 19854684036460, 476512419579196, 11912810484279600, 309733072600927300, 8362792960207653240, 234158202885844712475
Offset: 12
Keywords
Links
Programs
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Maple
a:=n->sum(n!*sum((-1)^k/(k-11)!, j=0..n), k=11..n): seq(-a(n)/12!, n=11..28); restart: G(x):=exp(-x)/(1-x)*(x^12/12!): f[0]:=G(x): for n from 1 to 29 do f[n]:=diff(f[n-1],x) od: x:=0: seq(f[n],n=12..28);# Zerinvary Lajos, Apr 03 2009
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Mathematica
With[{nn=40}, Drop[CoefficientList[Series[Exp[-x]/(1 - x) x^12/12!, {x, 0, nn}], x]Range[0, nn]!, 12]] (* Vincenzo Librandi, Feb 19 2014 *)
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PARI
x='x+O('x^66); Vec( serlaplace(exp(-x)/(1-x)*(x^12/12!)) ) \\ Joerg Arndt, Feb 19 2014
Formula
E.g.f.: exp(-x)/(1-x)*(x^12/12!). [Zerinvary Lajos, Apr 03 2009]
O.g.f.: (1/12!)*Sum_{k>=12} k!*x^k/(1 + x)^(k+1). - Ilya Gutkovskiy, Apr 15 2017
Extensions
Changed offset from 0 to 12 by Vincenzo Librandi, Feb 19 2014
Edited by Joerg Arndt, Feb 19 2014