OFFSET
0,10
COMMENTS
Number of partitions of n into parts 2, 7, 9, and 12. - Vincenzo Librandi, Jun 03 2014
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (0,1,0,0,0,0,1,0,0,0,-1,1,0,-1,0,-1,0,1,-1,0,0,0,1,0,0,0,0,1,0,-1).
FORMULA
a(n) = floor((n^3+45*n^2+672*n-1888)/9072 - (n mod 2)*n/48 + ((2*n^2+1) mod 3)*n/108 + ((6*n^3+4*n^2+5) mod 7)/7 + ((n^3+3*n^2+8*n+6) mod 9)/9 + (((n+7) mod 9) - ((n+6) mod 9) + 2*((n+5) mod 9) - 2*((n+4) mod 9))/27). - Hoang Xuan Thanh, Jun 13 2026
MATHEMATICA
CoefficientList[Series[1/((1 - x^2) (1 - x^7) (1 - x^9) (1 - x^12)), {x, 0, 100}], x] (* Vincenzo Librandi, Jun 03 2014 *)
PROG
(PARI) Vec(1/((1-x^2)*(1-x^7)*(1-x^9)*(1-x^12)) + O(x^80)) \\ Hoang Xuan Thanh, Jun 13 2026
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved
