OFFSET
0,2
LINKS
Index entries for linear recurrences with constant coefficients, signature (3,-3,1,1).
FORMULA
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) + a(n-4).
a(n) = Sum_{k=0..floor(n/4)} binomial(n+1-k,n-4*k).
PROG
(PARI) my(N=40, x='x+O('x^N)); Vec((1-x)/((1-x)^3-x^4))
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Seiichi Manyama, Aug 05 2024
STATUS
approved