OFFSET
1,6
EXAMPLE
The proper divisors of 16 are 1, 2, 4, 8. So a(16) = gcd(F(16), F(1)*F(2)*F(4)*F(8)) = gcd(987, 1*1*3*21) = 21.
MAPLE
with(combinat): with(numtheory): a:=proc(n) local div: div:=divisors(n): gcd(fibonacci(n), product(fibonacci(div[j]), j=1..tau(n)-1)): end: seq(a(n), n=1..65); # Emeric Deutsch, Oct 12 2005
MATHEMATICA
f[n_] := GCD[Fibonacci[n], Times @@ Fibonacci /@ Most[Divisors[n]]]; Table[ f[n], {n, 55}] (* Robert G. Wilson v, Oct 12 2005 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Leroy Quet, Oct 11 2005
EXTENSIONS
More terms from Robert G. Wilson v and Emeric Deutsch, Oct 12 2005
STATUS
approved