OFFSET
0,1
FORMULA
a(n) = a(n-13). - R. J. Mathar, May 30 2025
G.f.: -x^6*(1+x^2)*(x^4-x^2+1) / ( (x-1)*(1+x+x^2+x^3+x^4+x^5+x^6+x^7+x^8+x^9+x^10+x^11+x^12) ). - R. J. Mathar, May 30 2025
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Jan 13 2009
STATUS
approved
