A069110 Squarefree part of F(n) (the Fibonacci numbers): the smallest number such that a(n)*F(n) is a square.

1, 1, 2, 3, 5, 2, 13, 21, 34, 55, 89, 1, 233, 377, 610, 987, 1597, 646, 4181, 6765, 10946, 17711, 28657, 322, 3001, 121393, 196418, 317811, 514229, 208010, 1346269, 2178309, 3524578, 5702887, 9227465, 103683, 24157817, 39088169, 63245986

Offset: 1

Author

Benoit Cloitre, Apr 06 2002

Keywords

• easy
• nonn

Links

• Amiram Eldar, Table of n, a(n) for n = 1..1408 (terms 1..200 from Vincenzo Librandi)

Crossrefs

Cf. A007913.

Programs

Magma

[SquareFree(Fibonacci(n)): n in [1..20]]; // Vincenzo Librandi, Nov 13 2014

Mathematica

Column[Table[Times@@Power@@@({#[[1]], Mod[#[[2]], 2]}&/@FactorInteger[Fibonacci[n]]), {n, 20}]] (* Vincenzo Librandi, Nov 13 2014 *)

PARI

for(n=1,60,print1(core(fibonacci(n)),","))