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A192794 Numbers n such that n + 2 and n^2 + 4 are primes. 3
1, 3, 5, 15, 17, 27, 35, 45, 57, 65, 87, 95, 125, 135, 137, 147, 155, 177, 255, 267, 275, 347, 357, 407, 447, 455, 477, 507, 605, 615, 707, 717, 755, 767, 785, 795, 827, 837, 905, 935, 945, 1185, 1235, 1247, 1257, 1275, 1325, 1365, 1457, 1497, 1595, 1695 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..52.

EXAMPLE

1 + 2 = 3 and  1 + 4 = 5 are primes,

3 + 2 = 5 and  9 + 4 = 13 are primes,

5 + 2 = 7 and 25 + 4 = 29 are primes.

PROG

(PARI){a=2; forstep(n=1, 2000, 2, if(isprime(n+a)&&isprime(n^2+a^2), print1(n", ")))}

CROSSREFS

Cf. A070689.

Sequence in context: A103192 A097856 A071593 * A293001 A018358 A319583

Adjacent sequences:  A192791 A192792 A192793 * A192795 A192796 A192797

KEYWORD

nonn

AUTHOR

Zak Seidov, Dec 19 2012

STATUS

approved

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Last modified September 19 11:06 EDT 2019. Contains 327192 sequences. (Running on oeis4.)