OFFSET
0,2
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1,0,0,1).
FORMULA
a(n) = Sum_{k=0..floor(n/7)} binomial(n-3*k+3,n-7*k).
a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4) + a(n-7).
PROG
(PARI) my(N=40, x='x+O('x^N)); Vec(1/((1-x)^4-x^7))
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Seiichi Manyama, Jan 15 2026
STATUS
approved