A066941 Numbers k such that gcd(prime(k+1) + 1, prime(k) + 1) = 4.

4, 8, 14, 19, 22, 27, 31, 38, 46, 47, 48, 63, 75, 85, 90, 93, 94, 95, 114, 117, 124, 131, 143, 149, 153, 154, 155, 163, 181, 192, 207, 213, 224, 229, 232, 235, 241, 242, 247, 248, 249, 261, 276, 285, 299, 303, 304, 314, 327, 328, 333, 334, 335, 348, 364, 370

Offset: 1

Author

Benoit Cloitre, Jan 24 2002

Keywords

• nonn

Comments

Numbers k such that A063086(k) = 4. - Andrew Howroyd, Dec 10 2024

Links

• Harry J. Smith, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A063086, A066940, A066942, A066943, A066944, A067603, A067604.

Programs

Mathematica

Select[ Range[400], GCD[ Prime[ # + 1] + 1, Prime[ # ] + 1] == 4 & ]

PARI

isok(k) = { gcd(prime(k+1) + 1, prime(k) + 1) == 4 } \\ Harry J. Smith, Apr 10 2010

Extensions

Edited by Robert G. Wilson v, Feb 01 2002