OFFSET
0,5
COMMENTS
Number of compositions of 5*n-3 into parts 3 and 5.
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (5,-10,11,-5,1).
FORMULA
a(n) = A052920(5*n-3) for n > 0.
a(n) = 5*a(n-1) - 10*a(n-2) + 11*a(n-3) - 5*a(n-4) + a(n-5) for n > 5.
a(n) = Sum_{k=0..floor(n/3)} binomial(n-1+2*k,n-3*k).
PROG
(PARI) my(N=40, x='x+O('x^N)); Vec(1/(1-x^3/(1-x)^5))
(PARI) a(n) = sum(k=0, n\3, binomial(n-1+2*k, n-3*k));
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Seiichi Manyama, Feb 01 2024
STATUS
approved