A025825 Expansion of 1/((1-x^2)*(1-x^9)*(1-x^12)).

1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 1, 1, 2, 1, 2, 1, 2, 1, 3, 1, 3, 2, 3, 2, 4, 2, 4, 3, 4, 3, 5, 3, 5, 4, 5, 4, 7, 4, 7, 5, 7, 5, 8, 5, 8, 7, 8, 7, 10, 7, 10, 8, 10, 8, 12, 8, 12, 10, 12, 10, 14, 10, 14, 12, 14, 12, 16, 12, 16, 14, 16, 14, 19, 14, 19, 16, 19, 16, 21, 16, 21, 19, 21, 19, 24, 19, 24, 21, 24, 21, 27, 21, 27

Offset

0,13

Comments

Number of partitions of n into parts 2, 9, and 12. - Hoang Xuan Thanh, Sep 03 2025

Links

Table of n, a(n) for n=0..92.

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

Formula

a(n) = floor((n^2 + 19*n +369 + 4*n*((n+2) mod 3) + 9*(n+7)*(-1)^n)/432). - Hoang Xuan Thanh, Sep 03 2025

Prog

(PARI) a(n) = (n^2 + 19*n + 369 + 4*n*((n+2)%3) + 9*(n+7)*(-1)^n) \432 \\ Hoang Xuan Thanh, Sep 03 2025

Crossrefs

Sequence in context: A029426 A369916 A085342 * A293224 A082303 A316384

Adjacent sequences: A025822 A025823 A025824 * A025826 A025827 A025828

Keyword

nonn,easy

Author

N. J. A. Sloane

Extensions

a(72) onwards from Hoang Xuan Thanh, Sep 03 2025

Status

approved