OFFSET
1,2
COMMENTS
This sequence contains a 1 and all terms of sequence A092579 that are not prime Fibonacci numbers.
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
EXAMPLE
77 has the divisors 1,7,11,77. None of these divisors is a Fibonacci number >= 2. So 77 is included in the sequence.
MAPLE
q:= n-> not ormap(d-> (t-> issqr(t+4) or issqr(t-4)
)(5*d^2), numtheory[divisors](n) minus {1}):
select(q, [$1..250])[]; # Alois P. Heinz, Jul 15 2022
MATHEMATICA
fibQ[n_] := IntegerQ @ Sqrt[5 n^2 - 4] || IntegerQ @ Sqrt[5 n^2 + 4]; aQ[n_] := !AnyTrue[Rest[Divisors[n]], fibQ]; Select[Range[250], aQ] (* Amiram Eldar, Oct 06 2019 *)
PROG
(PARI) isfib1(n) = if (n>1, my(k=n^2); k+=(k+1)<<2; (issquare(k) || issquare(k-8)));
isok(k) = fordiv(k, d, if (isfib1(d), return(0))); 1; \\ Michel Marcus, Jul 15 2022
CROSSREFS
KEYWORD
nonn
AUTHOR
Leroy Quet, Nov 17 2008
EXTENSIONS
Extended by Ray Chandler, Nov 24 2008
STATUS
approved