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A182238 n^2 + {1,3,7} are primes. 2
2, 4, 10, 74, 146, 256, 440, 470, 584, 920, 1070, 1156, 1324, 1394, 1420, 2080, 2470, 2600, 3326, 3746, 4796, 5996, 6460, 7160, 7466, 8894, 9164, 9554, 9596, 10490, 10970, 11204, 11246, 11336, 11374, 12314, 12386, 13394, 14290, 15586, 16250, 16330, 17060 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Under Schinzel's hypothesis H, this sequence is infinite. - Charles R Greathouse IV, Apr 23 2012

LINKS

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

EXAMPLE

2^2+{1,3,7}= {5,7,11} all prime, 4^2+{1,3,7}= {17,19,23} all prime.

PROG

(PARI)

{ forstep ( n=2, 10^6, 2,

    ns = n * n;

    if ( ! isprime( ns+1 ), next() );

    if ( ! isprime( ns+3 ), next() );

    if ( ! isprime( ns+7 ), next() );

    print1(n, ", ");

); }

/* Joerg Arndt, Apr 22 2012 */

CROSSREFS

Intersection of A005574, A049422, A114270.

Sequence in context: A326949 A215439 A120402 * A110073 A090256 A270479

Adjacent sequences:  A182235 A182236 A182237 * A182239 A182240 A182241

KEYWORD

nonn

AUTHOR

Zak Seidov, Apr 20 2012

STATUS

approved

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Last modified February 17 02:22 EST 2020. Contains 331976 sequences. (Running on oeis4.)