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Search: id:A088878
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| A088878 |
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Prime numbers p such that 3p-2 is a prime. |
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29
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| 3, 5, 7, 11, 13, 23, 37, 43, 47, 53, 61, 67, 71, 103, 113, 127, 137, 163, 167, 181, 191, 193, 211, 251, 257, 263, 271, 277, 293, 307, 313, 331, 337, 347, 373, 401, 431, 433, 443, 461, 467, 487, 491, 523, 541, 557, 587, 593, 601, 673, 677, 727, 751, 757, 761
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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Indices of semiprime octagonal numbers. - Jonathan Vos Post (jvospost3(AT)gmail.com), Feb 16 2006
Daughter primes of order 1. - Artur Jasinski (grafix(AT)csl.pl), Dec 12 2007
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REFERENCES
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M. Cerasoli, F. Eugeni and M. Protasi, Elementi di Matematica Discreta, Bologna 1988
Emanuele Munarini and Norma Zagaglia Salvi, Matematica Discreta,UTET, CittaStudiEdizioni, Milano 1997
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LINKS
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Eric Weisstein's World of Mathematics, Octagonal Number.
Eric Weisstein's World of Mathematics, Semiprime.
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FORMULA
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Numbers n such that n*(3*n-2) is semiprime; n such that A000567(n) is an element of A001358; n such that A001222(A000567(n)) = 2; n such that [(3*n-2)*(3*n-1)*(3*n)]/[(3*n-2)+(3*n-1)+(3*n)] is semiprime; n such that n is prime and (3*n-2) is prime. - Jonathan Vos Post (jvospost3(AT)gmail.com), Feb 16 2006
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MATHEMATICA
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n = 1; a = {}; Do[If[PrimeQ[(Prime[k] + 2n)/(2n + 1)], AppendTo[a, (Prime[k] + 2n)/(2n + 1)]], {k, 1, 500}]; a - Artur Jasinski (grafix(AT)csl.pl), Dec 12 2007
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PROGRAM
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(MAGMA( [ p: p in PrimesUpTo(770) | IsPrime(3*p-2) ]; - Klaus Brockhaus, Dec 21 2008
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CROSSREFS
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Cf. A000040, A000567, A001222, A001358, A091179, A091180, A091181, A136019, A136020.
Sequence in context: A066651 A154319 A080114 this_sequence A153185 A155916 A038979
Adjacent sequences: A088875 A088876 A088877 this_sequence A088879 A088880 A088881
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KEYWORD
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easy,nonn
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AUTHOR
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Giovanni Teofilatto (g.teofilatto(AT)tiscalinet.it), Nov 27 2003
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EXTENSIONS
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Corrected and extended by Ray Chandler (rayjchandler(AT)sbcglobal.net), Dec 27 2003
Entry revised by N. J. A. Sloane (njas(AT)research.att.com), Nov 28 2006
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