A177139 Numbers n such that (3*n-4, 3*n-2) is a twin prime pair.

3, 5, 7, 11, 15, 21, 25, 35, 37, 47, 51, 61, 65, 67, 77, 81, 91, 95, 105, 117, 141, 145, 155, 175, 191, 201, 207, 215, 221, 271, 275, 277, 287, 295, 341, 345, 351, 355, 365, 385, 411, 427, 431, 435, 441, 477, 485, 495, 497

Offset: 1

Author

Roger L. Bagula, May 03 2010

Keywords

• nonn
• less
• easy

Links

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

Programs

Mathematica

Flatten[Table[If[PrimeQ[3*n - 2] && PrimeQ[3*n - 4], n, {}], {n, 1, 500}]]
Select[Range[500],And@@PrimeQ[3#-{4,2}]&] (* Harvey P. Dale, Jun 21 2012 *)

Formula

a(n) = (A001359(n+1)+4)/3 = 1+A014574(n+1)/3 = 1+A167379(n). [Eds., May 03 2010]

Extensions

Formula added by the Assoc. Eds. of the OEIS, May 03 2010.