OFFSET
0,1
FORMULA
a(n)= sum(L(k+1)*L(n+6-k), k=0..n) = (29*n+18)*F(n+1)+18*(n+1)*F(n), with F(n) := A000045(n) (Fibonacci).
G.f.: (18+11*x)*(1+2*x)/(1-x-x^2)^2.
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Wolfdieter Lang, Feb 15 2002
STATUS
approved