OFFSET
0,10
COMMENTS
Number of partitions of n into parts 4, 5, 6, and 9. - Hoang Xuan Thanh, Apr 16 2026
LINKS
Index entries for linear recurrences with constant coefficients, signature (0,0,0,1,1,1,0,0,0,-1,-1,0,-1,-1,0,0,0,1,1,1,0,0,0,-1).
FORMULA
G.f.: 1/((1-x^4)*(1-x^5)*(1-x^6)*(1-x^9)).
a(n) = a(n-4)+a(n-5)+a(n-6)-a(n-10)-a(n-11)-a(n-13)-a(n-14)+a(n-18)+a(n-19)+a(n-20)-a(n-24). - Wesley Ivan Hurt, Apr 22 2021
a(n) = floor((n^3+36*n^2+420*n+2248)/6480 - (n mod 2)*(n+6)/48 + ((2*n^2+1) mod 3)*(3*n+41)/162 - ((2*n^2+2*n) mod 3)*17/162 + ((4*n^3+4*n^2+2) mod 5)/5). - Hoang Xuan Thanh, Apr 16 2026
MATHEMATICA
CoefficientList[Series[1/((1-x^4)(1-x^5)(1-x^6)(1-x^9)), {x, 0, 100}], x] (* Jinyuan Wang, Mar 11 2020 *)
PROG
(PARI) Vec(1/((1-x^4)*(1-x^5)*(1-x^6)*(1-x^9)) + O(x^80)) \\ Hoang Xuan Thanh, Apr 16 2026
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved
