A294372 Expansion of (1-x)^4/(x^2 + 4*x + 1).
1, -8, 37, -144, 540, -2016, 7524, -28080, 104796, -391104, 1459620, -5447376, 20329884, -75872160, 283158756, -1056762864, 3943892700, -14718807936, 54931339044, -205006548240, 765094853916, -2855372867424, 10656396615780, -39770213595696, 148424457767004
Offset: 0
Links
- Seiichi Manyama, Table of n, a(n) for n = 0..1746
- Index entries for linear recurrences with constant coefficients, signature (-4,-1).
Programs
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PARI
N=66; x='x+O('x^N); Vec((1-x)^4/(x^2+4*x+1))
Formula
G.f.: 1/Sum_{k>=0} (k+1)^3*x^k.
From Colin Barker, Dec 19 2017: (Start)
a(n) = -6*sqrt(3)*((-2-sqrt(3))^n*(-2+sqrt(3)) + (-2+sqrt(3))^n*(2+sqrt(3))) for n > 2.
a(n) = -4*a(n-1) - a(n-2) for n > 4.
(End)