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A173207 Cubefree Fibonacci numbers which are not squarefree. 2
75025, 12586269025, 225851433717, 2111485077978050, 4660046610375530309, 354224848179261915075, 43566776258854844738105, 114059301025943970552219, 42230279526998466217810220532898, 1672445759041379840132227567949787325 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Subsequence of A061899. [R. J. Mathar, Feb 16 2010]
Apparently contains Fibonacci(25*m), m>0. - Ralf Stephan, Jan 26 2014
LINKS
FORMULA
A000045 INTERSECT A067259.
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
A173207_list = []
a, b = 1, 2
for _ in range(10**2):
....if max(factorint(b).values()) == 2:
........A173207_list.append(b)
....a, b = b, a + b # Chai Wah Wu, Jun 08 2015
CROSSREFS
Sequence in context: A210051 A179252 A045731 * A182809 A182393 A347848
KEYWORD
nonn
AUTHOR
EXTENSIONS
Converted cross-references to a formula - R. J. Mathar, Feb 16 2010
STATUS
approved

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Last modified June 19 03:10 EDT 2024. Contains 373492 sequences. (Running on oeis4.)