A165668 Primes of the form (p^2-2)/7, where p is also a prime number.

17, 41, 137, 401, 641, 761, 1697, 3257, 5657, 8297, 10337, 21617, 45281, 51257, 53681, 62417, 78017, 85361, 93497, 136361, 138041, 140297, 152441, 160817, 180161, 189257, 201281, 203321, 222857, 232961, 248537, 251561, 301601, 315881, 340121, 478937

Offset

1,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Formula

a(n) = (A165667(n)^2-2)/7.

Example

17=(11^2-2)/7; 41=(17^2-2)/7; 137=(31^2-2)/7.

Mathematica

Select[(#^2-2)/7&/@Prime[Range[300]], PrimeQ] (* Harvey P. Dale, Nov 10 2009 *)

Prog

(PARI) lista(nn) = forprime(p=2, nn, q=(p^2-2)/7; if ((type(q)=="t_INT") && isprime(q), print1(q, ", "))); \\ Michel Marcus, Aug 19 2015

Crossrefs

Cf. A165666, A165667.

Sequence in context: A205171 A070183 A201705 * A269425 A164602 A078847

Adjacent sequences: A165665 A165666 A165667 * A165669 A165670 A165671

Keyword

nonn,easy

Author

Vincenzo Librandi, Sep 24 2009

Extensions

Entries checked by R. J. Mathar and Charles R Greathouse IV, Oct 12 2009

Status

approved