A064321 a(n) = n*(n-1)^3*(n-2)^3*(n-3).
0, 0, 0, 0, 864, 17280, 144000, 756000, 2963520, 9483264, 26127360, 64152000, 143748000, 298995840, 584648064, 1085142240, 1926288000, 3290112000, 5433384960, 8710395264, 13600573920, 20741616000, 30968784000, 45361118880, 65295324864, 92508134400, 129168000000
Offset: 0
Examples
a(4) = 4*(3^3)*(2^3)*1 = 4*27*8*1 = 864.
Links
- Harry J. Smith, Table of n, a(n) for n = 0..400
- Index entries for linear recurrences with constant coefficients, signature (9,-36,84,-126,126,-84,36,-9,1).
Programs
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Maple
A064321:=n->n*(n-1)^3*(n-2)^3*(n-3); seq(A064321(n), n=0..50); # Wesley Ivan Hurt, Feb 02 2014
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Mathematica
Table[n (n - 3) (n - 1)^3*(n - 2)^3, {n, 0, 50}] (* Wesley Ivan Hurt, Feb 02 2014 *) -
PARI
a(n) = { n*(n - 1)^3*(n - 2)^3*(n - 3) } \\ Harry J. Smith, Sep 11 2009 -
PARI
concat([0,0,0,0], Vec(-288*x^4*(3*x^4+33*x^3+68*x^2+33*x+3)/(x-1)^9 + O(x^100))) \\ Colin Barker, Sep 14 2014
Formula
G.f.: -288*x^4*(3*x^4+33*x^3+68*x^2+33*x+3) / (x-1)^9. - Colin Barker, Sep 14 2014