A086175 Numbers n such that n*prime(n)-2 is prime.

3, 5, 21, 23, 25, 33, 37, 45, 57, 81, 83, 85, 93, 121, 123, 133, 137, 173, 183, 187, 193, 195, 215, 219, 225, 231, 245, 247, 285, 289, 295, 301, 315, 317, 327, 329, 353, 357, 359, 391, 395, 403, 419, 423, 429, 435, 447, 477, 479, 503, 513, 549, 561, 567, 571

Offset: 1

Author

Zak Seidov, Jul 11 2003

Keywords

• easy
• nonn

Comments

See also A086172, A086173, A086174, A086176, A086177.

Links

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

Crossrefs

Cf. A086172, A086173, A086174, A086176, A086177.

Programs

Magma

[n: n in [1..800] | IsPrime(n*NthPrime(n) - 2)]; // Vincenzo Librandi, Oct 05 2012

Mathematica

Select[Range[1000], PrimeQ[ # Prime[ # ]-2]&]