OFFSET
0,10
COMMENTS
Number of partitions of n into parts 3, 7, 9, and 12. - Hoang Xuan Thanh, Apr 10 2026
LINKS
Index entries for linear recurrences with constant coefficients, signature (0,0,1,0,0,0,1,0,1,-1,0,0,0,0,-1,-1,0,0,0,0,-1,1,0,1,0,0,0,1,0,0,-1).
FORMULA
a(n) = floor((2*n^3+135*n^2+2700*n+16004)/27216 - (n mod 3)*(n^2+31*n+216)/648 - ((2*n^2+2*n) mod 3)*n*7/648 + ((4*n^3+4*n^2+3*n+4) mod 7)/7). - Hoang Xuan Thanh, Apr 10 2026
MATHEMATICA
CoefficientList[Series[1/((1-x^3)(1-x^7)(1-x^9)(1-x^12)), {x, 0, 100}], x] (* Jinyuan Wang, Mar 12 2020 *)
PROG
(PARI) Vec(1/((1-x^3)*(1-x^7)*(1-x^9)*(1-x^12)) + O(x^80)) \\ Hoang Xuan Thanh, Apr 10 2026
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved
