A064836 a(n) = A064835(n)/2.

0, 0, 1, 5, 22, 60, 135, 261, 460, 752, 1165, 1725, 2466, 3420, 4627, 6125, 7960, 10176, 12825, 15957, 19630, 23900, 28831, 34485, 40932, 48240, 56485, 65741, 76090, 87612, 100395, 114525, 130096, 147200, 165937, 186405, 208710, 232956, 259255, 287717, 318460, 351600

Offset

0,4

Links

Harry J. Smith, Table of n, a(n) for n = 0..500

Index entries for linear recurrences with constant coefficients, signature (4,-5,0,5,-4,1).

Formula

G.f.: x^2*(1 + x + 7*x^2 - 3*x^3)/((1 - x)^5*(1 + x)). - Andrew Howroyd, Dec 29 2024

Prog

(PARI) a(n)={ (n^4/4 - 2*n^2 + 3*n - if (n%2, 5/4))/2 } \\ Harry J. Smith, Sep 28 2009

Crossrefs

Cf. A064835.

Sequence in context: A273685 A050533 A212094 * A273311 A288534 A286711

Adjacent sequences: A064833 A064834 A064835 * A064837 A064838 A064839

Keyword

nonn,easy

Author

N. J. A. Sloane, Oct 25 2001

Status

approved