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Search: id:A155900
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| A155900 |
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Numbers n such that Omega(n)=Omega(2^n-1), where Omega=A001222=number of prime factors counted with multiplicity. |
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+0
1
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| 1, 2, 3, 4, 5, 7, 8, 9, 13, 16, 17, 19, 27, 31, 32, 49, 61, 89, 107, 127
(list; graph; listen)
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OFFSET
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1,2
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COMMENT
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Mersenne prime exponents A000043 are a subsequence, with Omega(p)=Omega(2^p-1)=1.
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LINKS
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Davar55 et al., "Mersenne-Like", discussion on mersenneforum.org, Jan 27 2009.
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FORMULA
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{n: A046051(n)=A001222(n)} [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Mar 14 2009]
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PROGRAM
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(PARI) for( i=1, 999, bigomega(2^i-1)==bigomega(i) & print1(i", "))
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CROSSREFS
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Sequence in context: A160519 A051204 A102363 this_sequence A107684 A111796 A039124
Adjacent sequences: A155897 A155898 A155899 this_sequence A155901 A155902 A155903
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KEYWORD
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more,nonn
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AUTHOR
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M. F. Hasler (MHasler(AT)univ-ag.fr), Feb 01 2009
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