A181605 Twin primes ending in 7.

7, 17, 107, 137, 197, 227, 347, 617, 827, 857, 1277, 1427, 1487, 1607, 1667, 1697, 1787, 1877, 1997, 2027, 2087, 2237, 2267, 2657, 2687, 3167, 3257, 3467, 3527, 3557, 3767, 3917, 4127, 4157, 4217, 4337, 4517, 4547, 4637, 4787, 4967, 5417, 5477, 5657

Offset

1,1

Comments

First disagrees with A092340 at n=26: A092340 contains 2707, but this sequence doesn't. Is this a subsequence of A092340? - Nathaniel Johnston, Jun 25 2011

Yes, it is a subsequence of A092340: see link. - Robert Israel, Apr 13 2021

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Omar E. Pol, Determinacion geometrica de los numeros primos y perfectos

Robert Israel, A181605 is a subsequence of A092340

Formula

A001097 INTERSECT A030432. - R. J. Mathar, Nov 03 2010

Maple

[7, op(select(t -> isprime(t) and isprime(t+2), [seq(i, i=17..10000, 30)]))]; # Robert Israel, Apr 13 2021

Mathematica

Select[Prime@ Range@ 800, Mod[ #, 10] == 7 && (PrimeQ[ # - 2] || PrimeQ[ # + 2]) &] (* Robert G. Wilson v, Nov 06 2010 *)

Crossrefs

Cf. A001097, A092340, A181603, A181604, A181606.

Sequence in context: A092057 A082738 A092340 * A284209 A068172 A067185

Adjacent sequences: A181602 A181603 A181604 * A181606 A181607 A181608

Keyword

nonn,base

Author

Omar E. Pol, Nov 01 2010

Extensions

More terms from R. J. Mathar and Robert G. Wilson v, Nov 03 2010

Status

approved