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A139587 Non-Fibonacci numbers with non-Fibonacci number of divisors. 2
6, 10, 12, 14, 15, 18, 20, 22, 26, 27, 28, 32, 33, 35, 36, 38, 39, 44, 45, 46, 48, 50, 51, 52, 57, 58, 60, 62, 63, 64, 65, 68, 69, 72, 74, 75, 76, 77, 80, 82, 84, 85, 86, 87, 90, 91, 92, 93, 94, 95, 96, 98, 99, 100, 106, 108, 111 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
A000005(a(n)) is not a Fibonacci number.
LINKS
EXAMPLE
6 belongs to the sequence because it is not a Fibonacci number and its number of divisors, 4, is also not a Fibonacci number.
MATHEMATICA
With[{fibs=Fibonacci[Range[12]]}, Select[Range[Max[fibs]], FreeQ[fibs, #] && FreeQ[fibs, DivisorSigma[0, #]]&]] (* Harvey P. Dale, Jun 20 2021 *)
CROSSREFS
Non-Fibonacci number: A001690. Cf. A000005, A000045, A139095, A139586, A139588, A139589, A139590.
Sequence in context: A182301 A069059 A273157 * A201463 A119313 A362980
KEYWORD
easy,nonn
AUTHOR
Omar E. Pol, May 22 2008
EXTENSIONS
Example clarified by Harvey P. Dale, Jun 20 2021
STATUS
approved

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Last modified June 18 07:40 EDT 2024. Contains 373469 sequences. (Running on oeis4.)