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A127977 Arises in Shevelev's conjecture on evil primes and odious primes. +0
1
0, 2, 4, 7, 13, 19, 39, 54, 104, 139, 251, 334, 590, 716, 1353, 1855, 3659, 5221, 10484, 14933, 27491, 35474, 68816, 97342, 186405, 265255 (list; graph; listen)
OFFSET

1,2

COMMENT

Shevelev conjectures (p.2) that for all natural numbers n other than 5 and 6, the number of evil primes not exceeding n <= the number of odious primes not exceeding n. Odious primes are A000040 INTERSECTION A000069. Evil primes are A000040 INTERSECTION A001969. A000069 Odious numbers: odd number of 1's in binary expansion. A001969 Evil numbers: even number of 1's in binary expansion.

LINKS

Vladimir Shevelev, A Conjecture on Primes and a Step towards Justification, Jun 06 2007, table 1, p. 2, arXiv:0706.0786

FORMULA

a(n) = MIN[k in (2^(n-1),2^n)] ((the number of odious primes not exceeding k) - the number of evil primes not exceeding k)). a(n) = MIN[k in (2^(n-1),2^n)] (A027697(k) - A027699(k)).

CROSSREFS

Cf. A000040, A000069, A001969, A027697, A027699, A095005, A095006.

Sequence in context: A162842 A164901 A109853 this_sequence A112997 A037032 A165753

Adjacent sequences: A127974 A127975 A127976 this_sequence A127978 A127979 A127980

KEYWORD

easy,nonn,new

AUTHOR

Jonathan Vos Post (jvospost3(AT)gmail.com), Jun 07 2007

EXTENSIONS

Replaced arXiv URL by non-cached version - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Oct 30 2009

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Last modified November 25 20:09 EST 2009. Contains 167514 sequences.


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