OFFSET
1,2
LINKS
Seiichi Manyama, Table of n, a(n) for n = 1..1000
FORMULA
G.f. A(x) satisfies A(x) = x/(1 - 4*x) + A(x^4).
If n == 0 (mod 4), a(n) = 4^n + a(n/4) otherwise a(n) = 4^n.
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, May 30 2024
STATUS
approved