OFFSET
1,1
LINKS
FORMULA
a(n) = 7*a(n-1) + a(n-2) - 7*a(n-3).
G.f.: x*(2+x) / ( (x-1)*(7*x-1)*(1+x) ). - R. J. Mathar, Nov 21 2011
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
STATUS
approved