OFFSET
1,2
LINKS
FORMULA
a(n) = 7a(n-1) + a(n-2) - 7a(n-3).
a(n) = (-1)^n/16 -1/4 +3*7^n/16. G.f. x*(1+2*x) / ( (x-1)*(7*x-1)*(1+x) ). - R. J. Mathar, Nov 02 2011
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
STATUS
approved