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A250445
a(n) = gcd(n!, Fibonacci(n)) as n runs through A250444.
1
2, 3, 5, 2, 5, 13, 2, 37, 2, 13, 2, 3, 5, 5, 2, 73, 13, 5, 2, 3, 2, 5, 13, 89, 2, 3, 2, 2, 89, 5, 5, 157, 2, 13, 3, 2, 2, 89, 3, 193, 2, 13, 5, 3, 2, 5, 13, 2, 5, 3, 3, 2, 89, 5, 2, 3, 277, 13, 3, 5, 233, 13, 2, 5, 2, 313, 89, 2, 2, 13, 3, 2, 89, 5, 5, 13, 233, 2, 2, 397, 233, 3, 2, 3, 5
OFFSET
1,1
COMMENTS
By the definition of A250444, all terms are prime.
EXAMPLE
For n = 9, GCD(9!, Fibonacci(9)) = 2, (prime, thus belongs to the sequence).
MATHEMATICA
a[n_] := GCD[n!, Fibonacci[n]];
p[n_] := Which[PrimeQ[a[n]], a[n], PrimeQ[a[n]] == False, ];
Select[Table[p[n], {n, 1, 300}], IntegerQ[#] &]
PROG
(PARI) for(n=1, 10^3, if(isprime(p=gcd(n!, fibonacci(n))), print1(p, ", "))) \\ Derek Orr, Nov 23 2014
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
EXTENSIONS
More terms from Derek Orr, Nov 23 2014
STATUS
approved