

A089682


Primes of the form 3*m^2  1.


7



2, 11, 47, 107, 191, 431, 587, 971, 1451, 2027, 2351, 2699, 3467, 4799, 5807, 6911, 7499, 8111, 8747, 10091, 10799, 14699, 15551, 16427, 17327, 18251, 25391, 27647, 36299, 41771, 44651, 55487, 57131, 62207, 67499, 71147, 74891, 80687, 92927
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OFFSET

1,1


COMMENTS

431 and 27647 also have the form 2*m^31 (431 = 3*12^21 = 2*6^31 and 27647 = 3*96^21 = 2*24^31). [Howard Berman (howard_berman(AT)hotmail.com), May 09 2009]
Obviously m must be either 1 or an even number. So this consists of 1 together with primes of the form 12*u^2  1.  N. J. A. Sloane, Aug 09 2019


REFERENCES

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


LINKS



MATHEMATICA



PROG

(Magma) [a: n in [0..200]  IsPrime(a) where a is 3*n^21]; // Vincenzo Librandi, Jul 16 2012


CROSSREFS



KEYWORD

nonn,easy


AUTHOR



EXTENSIONS



STATUS

approved



