A008465 2^(2n-6) * C(n,3) - 2^(n-2) * C(n,4).

1, 12, 120, 1040, 7840, 52864, 327936, 1912320, 10644480, 57164800, 298428416, 1522626560, 7622451200, 37551144960, 182458122240, 875972788224, 4161315274752, 19583780782080, 91393766195200

Offset

3,2

Links

Table of n, a(n) for n=3..21.

Formula

(n-3)*(n-4)*a(n) -2*(9*n-35)*(n-4)*a(n-1) +80*(n-1)*(n-5)*a(n-2) -96*(n-1)*(n-2)*a(n-3)=0. - R. J. Mathar, Sep 21 2013

Maple

f := n->2^(2*n-6)*binomial(n, 3)-2^(n-2)*binomial(n, 4);

Mathematica

Table[2^(2n-6) Binomial[n, 3]-2^(n-2) Binomial[n, 4], {n, 3, 30}] (* Harvey P. Dale, Oct 12 2016 *)

Crossrefs

Sequence in context: A009035 A009140 A012273 * A291391 A115902 A277491

Adjacent sequences: A008462 A008463 A008464 * A008466 A008467 A008468

Keyword

nonn

Author

N. J. A. Sloane, Colin Mallows

Status

approved