OFFSET
0,4
COMMENTS
Number of partitions of n into parts 1, 3, 4 and 12. - Ilya Gutkovskiy, May 14 2017
LINKS
Index entries for linear recurrences with constant coefficients, signature (1,0,1,0,-1,0,-1,1,0,0,0,1,-1,0,-1,0,1,0,1,-1).
FORMULA
a(n) = floor((n^3 + 30*n^2 + 252*n + 846)/864 - (n/36)*[(n mod 3)=2] + ((n+2)/96)*((n mod 4)-2)^2). - Hoang Xuan Thanh, Jul 30 2025
MATHEMATICA
CoefficientList[Series[1/((1 - x)*(1 - x^3)*(1 - x^4)*(1 - x^12)), {x, 0, 52}], x] (* Hoang Xuan Thanh, Jul 30 2025 *)
PROG
(PARI) Vec(1/((1 - x)*(1 - x^3)*(1 - x^4)*(1 - x^12))+ O(x^53)) \\ Hoang Xuan Thanh, Jul 30 2025
(PARI) a(n) = (n^3 + 30*n^2 + 252*n + 846 + 9*(n+2)*((n%4)-2)^2 - 12*n*((n%3)*((n%3)-1)))\ 864 \\ Hoang Xuan Thanh, Aug 11 2025
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved
