A247193 - OEIS

A247193

a(n) = gcd(n!, Fibonacci(n)).

1, 1, 2, 3, 5, 8, 1, 21, 2, 5, 1, 144, 1, 13, 10, 21, 1, 136, 1, 165, 26, 1, 1, 46368, 25, 1, 34, 39, 1, 440, 1, 21, 2, 1, 65, 139536, 1, 37, 2, 1155, 1, 3016, 1, 129, 170, 1, 1, 4358592, 13, 275, 2, 3, 1, 136952, 5, 55419, 74, 1, 1, 10066320, 1, 1, 442, 987, 5, 8, 1, 201, 2, 20735, 1, 44930592, 1, 73, 3050, 111, 13, 8, 1, 2225685

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OFFSET

1,3

LINKS

Ivan Neretin, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = gcd(n!, Fibonacci(n)).

a(A069180(n)) == 1. - Michel Marcus, Nov 25 2014

EXAMPLE

For n = 8: GCD(8!, Fibonacci(8)) = 21.

MAPLE

seq(igcd(n!, combinat:-fibonacci(n)), n=1..100); # Robert Israel, Nov 24 2014