OFFSET
0,21
COMMENTS
a(n) is the number of partitions of n into parts 6, 7, and 10. - Joerg Arndt, Jan 23 2024
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..5000
Index entries for linear recurrences with constant coefficients, signature (0,0,0,0,0,1,1,0,0,1,0,0,-1,0,0,-1,-1,0,0,0,0,0,1).
FORMULA
a(n) = floor((n^2+23*n+403)/840 + (n+12)*(-1)^n/120 + ((6*n^2+5*n+3) mod 7)/7). - Hoang Xuan Thanh, Sep 24 2025
MATHEMATICA
CoefficientList[Series[1/((1-x^6)(1-x^7)(1-x^10)), {x, 0, 100}], x](* Harvey P. Dale, Jul 20 2021 *)
PROG
(Magma) R<x>:=PowerSeriesRing(Integers(), 100); Coefficients(R!( 1/((1-x^6)*(1-x^7)*(1-x^(10))) )); // G. C. Greubel, Jan 23 2024
(SageMath)
def A025899_list(prec):
P.<x> = PowerSeriesRing(ZZ, prec)
return P( 1/((1-x^6)*(1-x^7)*(1-x^(10)))).list()
A025899_list(100) # G. C. Greubel, Jan 23 2024
(PARI) a(n) = (n^2+23*n+403 + 7*(n+12)*(-1)^n + 120*((6*n^2+5*n+3)%7))\840 \\ Hoang Xuan Thanh, Sep 24 2025
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved
