OFFSET
0,3
COMMENTS
Number of partitions of n into parts 1, 2, 9 and 12. - Ilya Gutkovskiy, May 14 2017
LINKS
Index entries for linear recurrences with constant coefficients, signature (1,1,-1,0,0,0,0,0,1,-1,-1,2,-1,-1,1,0,0,0,0,0,-1,1,1,-1).
FORMULA
G.f.: 1/((1-x)(1-x^2)(1-x^9)(1-x^12)).
a(n) = floor((n^3+36*n^2+357*n+1520)/1296 + ((n+16)/108)*[(n mod 3)=0] + ((n+8)/48)*[(n mod 2)=0]). - Hoang Xuan Thanh, Jul 17 2025
MATHEMATICA
CoefficientList[Series[1/((1 - x) (1 - x^2) (1 - x^9) (1 - x^12)), {x, 0, 80}], x] (* Wesley Ivan Hurt, Feb 15 2017 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
EXTENSIONS
a(54) onwards from Hoang Xuan Thanh, Jul 17 2025
STATUS
approved