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A245987 Number of pairs of endofunctions f, g on [n] satisfying g^10(f(i)) = f(i) for all i in [n]. 2
1, 1, 10, 213, 8056, 540945, 55791936, 7976641981, 1469902760320, 332703236420577, 93998774487116800, 34310097895273565541, 16097501586129903138816, 9217140995822760715385905, 6076268404868213191347785728, 4448129862114255651329796526125 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..100

MAPLE

with(combinat): M:=multinomial:

b:= proc(n, k) local l, g; l, g:= [1, 2, 5, 10],

      proc(k, m, i, t) option remember; local d, j; d:= l[i];

        `if`(i=1, n^m, add(M(k, k-(d-t)*j, (d-t)$j)/j!*

         (d-1)!^j *M(m, m-t*j, t$j) *g(k-(d-t)*j, m-t*j,

        `if`(d-t=1, [i-1, 0], [i, t+1])[]), j=0..min(k/(d-t),

        `if`(t=0, [][], m/t))))

      end; g(k, n-k, nops(l), 0)

    end:

a:= n-> add(b(n, j)*stirling2(n, j)*binomial(n, j)*j!, j=0..n):

seq(a(n), n=0..20);

CROSSREFS

Column k=10 of A245980.

Sequence in context: A280903 A239770 A239771 * A245981 A245985 A309737

Adjacent sequences:  A245984 A245985 A245986 * A245988 A245989 A245990

KEYWORD

nonn

AUTHOR

Alois P. Heinz, Aug 08 2014

STATUS

approved

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Last modified April 3 17:03 EDT 2020. Contains 333197 sequences. (Running on oeis4.)