A292979 Expansion of e.g.f. exp(x^4 * exp(x)).
1, 0, 0, 0, 24, 120, 360, 840, 21840, 365904, 3633840, 26619120, 239512680, 3943797000, 69258333144, 997361197560, 12707273822880, 179576670930720, 3215428464641760, 62865157116396384, 1167555972633639480, 20756362432008412440, 386561667091927394760
Offset: 0
Keywords
Links
- Seiichi Manyama, Table of n, a(n) for n = 0..487
Programs
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PARI
x='x+O('x^66); Vec(serlaplace(exp(x^4*exp(x))))
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PARI
a(n) = n!*sum(k=0, n\4, k^(n-4*k)/(k!*(n-4*k)!)); \\ Seiichi Manyama, Jul 10 2022
Formula
a(n) = (-1)^n * A292969(n).
a(n) = n! * Sum_{k=0..floor(n/4)} k^(n-4*k)/(k! * (n-4*k)!). - Seiichi Manyama, Jul 10 2022