A144834 Numbers n such that the two numbers n+1 and n+3 are both prime.

2, 4, 10, 16, 28, 40, 58, 70, 100, 106, 136, 148, 178, 190, 196, 226, 238, 268, 280, 310, 346, 418, 430, 460, 520, 568, 598, 616, 640, 658, 808, 820, 826, 856, 880, 1018, 1030, 1048, 1060, 1090, 1150, 1228, 1276, 1288, 1300, 1318, 1426, 1450, 1480, 1486, 1606

Offset

1,1

Comments

1 less than the lesser of each twin prime pair. [Harvey P. Dale, Nov 08 2011]

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Formula

a(n) = A014574(n)-2 = A001359(n)-1. - R. J. Mathar, Sep 24 2008

Mathematica

Transpose[Select[Partition[Prime[Range[300]], 2, 1], Last[#]-First[#] == 2&]][[1]]-1 (* Harvey P. Dale, Nov 08 2011 *)

Crossrefs

Cf. A053319 (first differences).

Sequence in context: A123689 A137928 A293154 * A006584 A280186 A032246

Adjacent sequences: A144831 A144832 A144833 * A144835 A144836 A144837

Keyword

easy,nonn

Author

Giovanni Teofilatto, Sep 22 2008

Extensions

Definition edited and extended by R. J. Mathar, Sep 24 2008

Status

approved