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A139588
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Nonprime numbers with Fibonacci number of divisors.
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3
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1, 4, 9, 16, 24, 25, 30, 40, 42, 49, 54, 56, 66, 70, 78, 81, 88, 102, 104, 105, 110, 114, 121, 128, 130, 135, 136, 138, 152, 154, 165, 169, 170, 174, 182, 184, 186, 189, 190, 195, 222, 230, 231, 232, 238, 246, 248, 250, 255, 258, 266, 273, 282, 285, 286, 289
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OFFSET
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1,2
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COMMENTS
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A000005(a(n)) is a Fibonacci number.
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LINKS
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FORMULA
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MATHEMATICA
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Module[{fibs=Fibonacci[Range[20]]}, Select[Range[300], !PrimeQ[#]&&MemberQ[ fibs, DivisorSigma[0, #]]&]] (* Harvey P. Dale, Jan 20 2023 *)
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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