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A224990 Primes p such that q = 2*p^2 - 1 and 2*p*q - 1 are also prime. 1
3, 13, 157, 181, 739, 829, 937, 1009, 1093, 1483, 1621, 1879, 2311, 2503, 2647, 2719, 3079, 4969, 4999, 5209, 5431, 5569, 6163, 6961, 8161, 8329, 9349, 9631, 10399, 10459, 10531, 10657, 11131, 11953, 13063, 18523, 20149, 20731, 21391, 21589, 26317, 27481, 28111, 28351, 29023 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Subsequence of A106483, and more elementary version of A224614.

LINKS

Table of n, a(n) for n=1..45.

MATHEMATICA

Select[Prime[Range[10000]], PrimeQ[2#^2 - 1] && PrimeQ[4#^3 - 2# - 1] &] (* Alonso del Arte, Apr 22 2013 *)

PROG

(PARI) forprime(p=1, 3e4, isprime(r=2*p^2-1)&&isprime(2*p*r-1)&&print1(p", "))

CROSSREFS

Sequence in context: A317074 A230036 A014376 * A065622 A246418 A140421

Adjacent sequences:  A224987 A224988 A224989 * A224991 A224992 A224993

KEYWORD

nonn

AUTHOR

M. F. Hasler, Apr 22 2013

STATUS

approved

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Last modified April 23 03:26 EDT 2019. Contains 322380 sequences. (Running on oeis4.)