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A002648 Cuban primes: p = (x^3 - y^3 )/(x - y), x=y+2.
(Formerly M4910 N2105)
+0
3
13, 109, 193, 433, 769, 1201, 1453, 2029, 3469, 3889, 4801, 10093, 12289, 13873, 18253, 20173, 21169, 22189, 28813, 37633, 43201, 47629, 60493, 63949, 65713, 69313, 73009, 76801, 84673, 106033, 108301, 112909, 115249, 129793, 139969 (list; graph; listen)
OFFSET

1,1

COMMENT

Primes p such that p = 1+3n^2 for some integer n. - Michael Somos Sep 15 2005

REFERENCES

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

A. J. C. Cunningham, Binomial Factorisations, Vols. 1-9, Hodgson, London, 1923-1929; see Vol. 1, pp. 245-259.

LINKS

Wikipedia, Cuban prime

Eric Weisstein's World of Mathematics, Cuban Prime

PROGRAM

(PARI) {a(n)= local(m, c); if(n<1, 0, c=0; m=1; while( c<n, m++; if( isprime(m)&issquare((m-1)/3), c++)); m)} /* Michael Somos Sep 15 2005 */

CROSSREFS

Cf. A002407.

Sequence in context: A084901 A006239 A142040 this_sequence A055840 A163845 A075143

Adjacent sequences: A002645 A002646 A002647 this_sequence A002649 A002650 A002651

KEYWORD

nonn

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com).

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Last modified November 27 14:50 EST 2009. Contains 167570 sequences.


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