OFFSET
1,1
LINKS
Chai Wah Wu, Table of n, a(n) for n = 1..472
EXAMPLE
F(4) = 3; 3 != x^2 + y^2 as no positive integers x, y >= 0 are the solution of this Diophantine equation.
MATHEMATICA
Select[Fibonacci[Range[65]], SquaresR[2, #] == 0 &] (* Amiram Eldar, Aug 29 2022 *)
PROG
(PARI) is(n)=if(n%4==3, return(1)); my(f=factor(n)); for(i=1, #f~, if(f[i, 1]%4==3 && f[i, 2]%2, return(1))); 0; \\ A022544
lista(nn) = select(is, apply(fibonacci, [1..nn])); \\ Michel Marcus, Sep 04 2022
(Python)
from itertools import islice
from sympy import factorint
def A356809_gen(): # generator of terms
a, b = 1, 2
while True:
if any(p&3==3 and e&1 for p, e in factorint(a).items()):
yield a
a, b = b, a+b
CROSSREFS
KEYWORD
nonn
AUTHOR
Ctibor O. Zizka, Aug 29 2022
STATUS
proposed