OFFSET
0,6
COMMENTS
Number of partitions of n into parts 1, 5, 9 and 10. - Ilya Gutkovskiy, May 21 2017
LINKS
Matthew House, Table of n, a(n) for n = 0..10000
Index entries for linear recurrences with constant coefficients, signature (1,0,0,0,1,-1,0,0,1,0,-1,0,0,-1,0,1,0,0,-1,1,0,0,0,1,-1).
FORMULA
a(n) = floor(n^3/2700 + n^2/72 + 121*n/900 + 65/48 + (n/50)*((3*n^2+3) mod 5) +(-1)^floor(n/5)*(5-2*(n mod 5))/16 + (144*(n mod 5)^3-405*(n mod 5)^2-1575*(n mod 5))/5400). - Hoang Xuan Thanh, Mar 12 2026
MATHEMATICA
CoefficientList[Series[1/((1-x)*(1-x^5)*(1-x^9)*(1-x^10)), {x, 0, 60}], x] (* Hoang Xuan Thanh, Jul 25 2025 *)
PROG
(PARI) a(n) = floor((2*n^3 + 75*n^2 + 834*n + 5625)/5400 + (n/50) * [2, 0, -1, -1, 0][n%5+1] + (1/15) * [10, 5, -1, -5, -5, 0, 0, -5, -5, 0][n%10+1]) \\ Hoang Xuan Thanh, Jul 25 2025
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved
