OFFSET
0,3
COMMENTS
Number of partitions of n into parts 1, 2, 5, and 12. - Joerg Arndt, May 20 2014
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (1, 1, -1, 0, 1, -1, -1, 1, 0, 0, 0, 1, -1, -1, 1, 0, -1, 1, 1, -1).
MAPLE
M := Matrix(20, (i, j)-> if (i=j-1) or (j=1 and member(i, [1, 2, 5, 8, 12, 15, 18, 19])) then 1 elif j=1 and member(i, [3, 6, 7, 13, 14, 17, 20]) then -1 else 0 fi); a := n -> (M^(n))[1, 1]; seq (a(n), n=0..51); # Alois P. Heinz, Jul 25 2008
MATHEMATICA
s = 1/((1-x)(1-x^2)(1-x^5)(1-x^12)) + O[x]^100; CoefficientList[s, x] (* Jean-François Alcover, Nov 05 2015 *)
LinearRecurrence[{1, 1, -1, 0, 1, -1, -1, 1, 0, 0, 0, 1, -1, -1, 1, 0, -1, 1, 1, -1}, {1, 1, 2, 2, 3, 4, 5, 6, 7, 8, 10, 11, 14, 15, 18, 20, 23, 26, 29, 32}, 80] (* Harvey P. Dale, Jun 22 2017 *)
PROG
(PARI) a(n)=floor((2*n^3+60*n^2+513*n+1773)/1440+(n+1)*(-1)^n/96+[0, -1, 0, 1, 0, 2][n%6+1]*(-1)^(n\6)/6) \\ Tani Akinari, May 19 2014
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved