A182238 n^2 + {1,3,7} are primes.

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

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