OFFSET
0,7
COMMENTS
Number of partitions of n into parts 2, 3, 6, and 7. - Joerg Arndt, Aug 13 2013
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (0,1,1,0,-1,1,1,-1,-2,-1,1,1,-1,0,1,1,0,-1).
FORMULA
a(n) = floor((n^3+27*n^2+306*n+1512)/1512 - (n+9)*(n mod 2)/24 - n*((n^2) mod 3)/18). - Hoang Xuan Thanh, Oct 02 2025
MATHEMATICA
CoefficientList[Series[1/((1 - x^2) (1 - x^3) (1 - x^6) (1 - x^7)), {x, 0, 100}], x] (* Vincenzo Librandi, Aug 13 2013 *)
PROG
(PARI) Vec(1/((1-x^2)*(1-x^3)*(1-x^6)*(1-x^7))+O(x^99)) \\ Charles R Greathouse IV, Sep 27 2012
(PARI) a(n) = (n^3+27*n^2+306*n+1512 - 63*(n+9)*(n%2) - 84*n*((n^2)%3))\1512 \\ Hoang Xuan Thanh, Oct 02 2025
(Magma) m:=80; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/((1-x^2)*(1-x^3)*(1-x^6)*(1-x^7)))); // Vincenzo Librandi, Aug 13 2013
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved
