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A238497
Cubefree Fibonacci numbers.
1
1, 1, 2, 3, 5, 13, 21, 34, 55, 89, 233, 377, 610, 987, 1597, 4181, 6765, 10946, 17711, 28657, 75025, 121393, 196418, 317811, 514229, 1346269, 2178309, 3524578, 5702887, 9227465, 24157817, 39088169, 63245986, 102334155, 165580141, 433494437
OFFSET
1,3
LINKS
FORMULA
A010056(a(n)) * A212793(a(n)) = 1. - Reinhard Zumkeller, Feb 28 2014
EXAMPLE
a(21) = 75025 since 75025 = fib(25) = 5^2 * 3001 has no cubic factor.
MATHEMATICA
Select[Fibonacci@ Range@ 120, Max[Last /@ FactorInteger@ #] < 3 &] (* Giovanni Resta, Feb 27 2014 *)
PROG
(Haskell)
a238497 n = a238497_list !! (n-1)
a238497_list = filter ((== 1) . a212793) $ tail a000045_list
-- Reinhard Zumkeller, Feb 28 2014
CROSSREFS
Intersection of A004709 and A000045.
Sequence in context: A145908 A173830 A224223 * A061305 A177374 A142881
KEYWORD
nonn
AUTHOR
Carmine Suriano, Feb 27 2014
EXTENSIONS
b-file corrected from Giovanni Resta, Frb 28 2014
STATUS
approved