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

1,3

Links

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

Mathematica

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

Prog

(PARI) for(n=1, 60, print1(core(fibonacci(n)), ", "))
(Magma) [SquareFree(Fibonacci(n)): n in [1..20]]; // Vincenzo Librandi, Nov 13 2014

Crossrefs

Cf. A007913.

Sequence in context: A060385 A080648 A113195 * A238684 A352377 A202694

Adjacent sequences: A069107 A069108 A069109 * A069111 A069112 A069113

Keyword

easy,nonn

Author

Benoit Cloitre, Apr 06 2002

Status

approved