OFFSET
1,2
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
FORMULA
a(n) = n/A054495(n).
EXAMPLE
a(10)=5 because 1, 2 and 5 are the Fibonacci numbers which divide 10 and 5 is the largest.
MATHEMATICA
With[{fibs=Fibonacci[Range[20]]}, Table[Max[Select[fibs, Divisible[ n, #]&]], {n, 100}]] (* Harvey P. Dale, Jul 17 2012 *)
PROG
(PARI) A010056(n)=my(k=n^2); k+=(k+1)<<2; issquare(k) || (n>0 && issquare(k-8))
a(n)=fordiv(n, d, if(A010056(n/d), return(n/d))) \\ Charles R Greathouse IV, Nov 05 2014
(Python)
from sympy import divisors
from sympy.ntheory.primetest import is_square
def A054494(n): return next(d for d in sorted(divisors(n, generator=True), reverse=True) if is_square(m:=5*d**2-4) or is_square(m+8)) # Chai Wah Wu, May 06 2024
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Henry Bottomley, Apr 04 2000
EXTENSIONS
Corrected by Harvey P. Dale, Jul 17 2012
STATUS
approved