

A225098


Numbers n such that n^2  2 and 2*n^2  1 are both prime.


0



2, 3, 7, 13, 15, 21, 43, 49, 63, 69, 127, 155, 183, 211, 231, 237, 259, 265, 273, 293, 301, 323, 335, 391, 435, 441, 447, 489, 505, 573, 595, 671, 713, 715, 743, 757, 797, 811, 951, 959, 973, 979, 987, 993, 1035, 1147, 1197, 1287, 1359, 1393, 1415, 1429, 1443, 1491, 1525, 1597, 1617, 1653
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OFFSET

1,1


COMMENTS

Primes in the sequence: 2, 3, 7, 13, 43, 127, 211, 293, 743, 757, 797, 811, 1429,...


LINKS

Table of n, a(n) for n=1..58.


EXAMPLE

2^2  2 = 2 is prime and 2*2^2  1 = 7 is prime, so a(2) = 2.


MATHEMATICA

Select[Range[1653], PrimeQ[#^2  2] && PrimeQ[2*#^2  1] &] (* T. D. Noe, May 10 2013 *)


CROSSREFS

Cf. A028870, A066049.
Sequence in context: A286176 A318401 A322703 * A101739 A141633 A045327
Adjacent sequences: A225095 A225096 A225097 * A225099 A225100 A225101


KEYWORD

nonn


AUTHOR

Gerasimov Sergey, Apr 27 2013


EXTENSIONS

Corrected by R. J. Mathar, May 05 2013


STATUS

approved



