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A181062
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Prime powers minus 1.
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5
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0, 1, 2, 3, 4, 6, 7, 8, 10, 12, 15, 16, 18, 22, 24, 26, 28, 30, 31, 36, 40, 42, 46, 48, 52, 58, 60, 63, 66, 70, 72, 78, 80, 82, 88, 96, 100, 102, 106, 108, 112, 120, 124, 126, 127, 130, 136, 138, 148, 150, 156, 162, 166, 168, 172, 178, 180, 190, 192, 196, 198, 210, 222, 226
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OFFSET
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1,3
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COMMENTS
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If 0 is excluded, possible lengths of a positive integer's longest string of consecutive divisors: range of values of A055874.
a(n) = largest number m such that A051451(n) = A003418(m).
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LINKS
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Table of n, a(n) for n=1..64.
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FORMULA
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a(n) = A000961(n)-1.
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EXAMPLE
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Any integer that is divisible by 5 consecutive integers will be divisible by at least 6 consecutive integers. Hence 5 is not in the sequence.
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MATHEMATICA
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Select[Table[n, {n, 2, 350}], Length[FactorInteger[#]] == 1 &] - 1 (* From Vladimir Joseph Stephan Orlovsky, Jun 28 2011 *)
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PROG
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(PARI) isA181061(n)=ispower(n++, , &n); isprime(n) \\ Charles R Greathouse IV, Jun 29 2011
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CROSSREFS
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Cf. A000961, A181063, A181064, A181121. Includes A006093 as a subsequence.
Sequence in context: A065609 A221178 A080389 * A091199 A093452 A082103
Adjacent sequences: A181059 A181060 A181061 * A181063 A181064 A181065
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KEYWORD
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easy,nonn,changed
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AUTHOR
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Matthew Vandermast, Oct 07 2010
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EXTENSIONS
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Entry revised by N. J. A. Sloane, Jan 06 2013
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STATUS
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approved
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