A243811 Numbers k such that 2*k+3 and 2*k+5 are both prime.

0, 1, 4, 7, 13, 19, 28, 34, 49, 52, 67, 73, 88, 94, 97, 112, 118, 133, 139, 154, 172, 208, 214, 229, 259, 283, 298, 307, 319, 328, 403, 409, 412, 427, 439, 508, 514, 523, 529, 544, 574, 613, 637, 643, 649, 658, 712, 724, 739, 742, 802, 808, 832, 847, 859, 892, 934

Offset: 1

Author

Vincenzo Librandi, Jun 11 2014

Keywords

• nonn
• easy
• less

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A040040, A067076, A089038.

Programs

Magma

[n: n in [0..1000] | IsPrime(2*n+3) and IsPrime(2*n+5)];

Mathematica

Select[Range[0, 1000], PrimeQ[2 # + 3] && PrimeQ[2 # + 5] &]

Formula

a(n) = A040040(n)-2.