OFFSET
1,4
FORMULA
a(n) = a(n-1)+a(n-2)+1 if n mod 4 = 0, else a(n) = a(n-1)+a(n-2), with offset 0. [Gary Detlefs, Dec 05 2010]
PROG
(PARI) a(n) = sum(k=1, n, issquare(8*k+9)*fibonacci(n-k+1)); \\ Michel Marcus, Jan 26 2023
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
More terms from Michel Marcus, Jan 26 2023
STATUS
approved