OFFSET
1,2
LINKS
Indranil Ghosh, Table of n, a(n) for n = 1..5000
Paolo Leonetti, Carlo Sanna, On the greatest common divisor of n and the nth Fibonacci number, arXiv:1704.00151 [math.NT], 2017. See l(n) on page 2.
FORMULA
For p prime (except 5), a(p) = p*A001177(p). See Leonetti & Sanna link.
MATHEMATICA
z[n_]:=Block[{k=1}, While[Mod[Fibonacci[k], n]!=0, k ++]; k]; a[n_]:=LCM[n, z[n]]; Table[a[n], {n, 100}] (* Indranil Ghosh, Apr 09 2017 *)
PROG
(PARI) z(n) = {my(k = 1); while (fibonacci(k) % n, k++); k; }
a(n) = lcm(n, z(n));
(Python)
from sympy import fibonacci, lcm
def z(n):
k=1
while fibonacci(k)%n: k+=1
return k
def a(n): return lcm(n, z(n))
print([a(n) for n in range(1, 201)]) # Indranil Ghosh, Apr 09 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Michel Marcus, Apr 09 2017
STATUS
approved