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A091348

a(n) = 24*5^n - 60*4^n + 50*3^n - 15*2^n + 1.

0, 1, 31, 391, 3451, 25231, 164731, 999391, 5767051, 32122831, 174397531, 929043391, 4879252651, 25349936431, 130617150331, 668714319391, 3406562690251, 17286209766031, 87448932863131, 441329102667391, 2223021985199851, 11180731992411631, 56166496811775931, 281884877304327391

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OFFSET

0,3

LINKS

Table of n, a(n) for n=0..23.

Index entries for linear recurrences with constant coefficients, signature (15,-85,225,-274,120).

FORMULA

a(n) = Sum_{i=1..n} i!*i^4*Stirling2(n, i)*(-1)^(n-i).

MATHEMATICA

Table[24*5^n - 60*4^n + 50*3^n - 15*2^n + 1, {n, 0, 25}]

PROG

(PARI) a(n) = sum(i=1, n, i!*i^4*stirling(n, i, 2)*(-1)^(n-i)); \\ Michel Marcus, Oct 21 2022