OFFSET
0,2
LINKS
Index entries for linear recurrences with constant coefficients, signature (9,-28,56,-70,56,-28,8,-1).
FORMULA
a(n) = A005710(8*n).
a(n) = Sum_{k=0..n} binomial(n+7*k,n-k).
a(n) = 9*a(n-1) - 28*a(n-2) + 56*a(n-3) - 70*a(n-4) + 56*a(n-5) - 28*a(n-6) + 8*a(n-7) - a(n-8).
G.f.: 1/(1 - x - x/(1 - x)^7).
PROG
(PARI) a(n) = sum(k=0, n, binomial(n+7*k, n-k));
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Seiichi Manyama, Jun 22 2024
STATUS
approved