

A173207


Cubefree Fibonacci numbers which are not squarefree.


2



75025, 12586269025, 225851433717, 2111485077978050, 4660046610375530309, 354224848179261915075, 43566776258854844738105, 114059301025943970552219, 42230279526998466217810220532898, 1672445759041379840132227567949787325
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OFFSET

1,1


COMMENTS

Apparently contains Fibonacci(25*m), m>0.  Ralf Stephan, Jan 26 2014


LINKS



FORMULA



MATHEMATICA

f[n_]:=Union[Last/@FactorInteger[n]][[ 1]]; lst={}; Do[fibo=Fibonacci[n]; If[f[fibo]==2, AppendTo[lst, fibo]], {n, 3, 2*5!}]; lst


PROG

(Python)
from sympy import factorint
a, b = 1, 2
for _ in range(10**2):
....if max(factorint(b).values()) == 2:


CROSSREFS



KEYWORD

nonn


AUTHOR



EXTENSIONS

Converted crossreferences to a formula  R. J. Mathar, Feb 16 2010


STATUS

approved



