OFFSET
1,1
COMMENTS
Except for a(1) = 5 all a(n) are congruent to 1 (mod 10) (final digit is 1). Final digit of most prime divisors of F(5n) is 1.
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..284
FORMULA
a(n) = A060385(5*n).
EXAMPLE
a(2) = 11 because F(10)= 5 * 11.
a(4) = 41 because F(20)= 3 * 5 * 11 * 41.
a(10) = 3001 because F(50)= 5^2 * 11 * 101 * 151 * 3001.
a(25) = 158414167964045700001 because F(125)= 5^3 * 3001 * 158414167964045700001.
MATHEMATICA
Table[Max[Flatten[FactorInteger[Fibonacci[5n]]]], {n, 1, 50}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Alexander Adamchuk, Aug 14 2006
EXTENSIONS
a(27)-a(29) from Amiram Eldar, Aug 01 2024
STATUS
approved