A011890 [ n(n-1)(n-2)/8 ].

0, 0, 0, 0, 3, 7, 15, 26, 42, 63, 90, 123, 165, 214, 273, 341, 420, 510, 612, 726, 855, 997, 1155, 1328, 1518, 1725, 1950, 2193, 2457, 2740, 3045, 3371, 3720, 4092, 4488, 4908, 5355, 5827, 6327, 6854, 7410

Offset

0,5

Links

Table of n, a(n) for n=0..40.

Index entries for linear recurrences with constant coefficients, signature (3, -3, 1, 0, 0, 0, 0, 1, -3, 3, -1).

Formula

a(n) = +3*a(n-1) -3*a(n-2) +a(n-3) +a(n-8) -3*a(n-9) +3*a(n-10) -a(n-11). G.f.: x^4*(3-2*x+3*x^2-x^3+2*x^4+x^6) / ( (-1+x)^4*(1+x)*(1+x^2)*(1+x^4) ). [From R. J. Mathar, Apr 15 2010]

Crossrefs

Sequence in context: A328688 A291651 A078869 * A131076 A001648 A051054

Adjacent sequences: A011887 A011888 A011889 * A011891 A011892 A011893

Keyword

nonn

Author

N. J. A. Sloane.

Status

approved