A138656 Primes p such that 42*p - 1 and 42*p + 1 are twin primes.

11, 31, 41, 101, 131, 211, 239, 331, 419, 421, 509, 619, 691, 751, 769, 1091, 1129, 1279, 1531, 1571, 1609, 1901, 2111, 2221, 2251, 2281, 2341, 2699, 2719, 2879, 2971, 3221, 3541, 3671, 3821, 3851, 4271, 4349, 4421, 4519, 4561, 4651, 4861, 4909, 4969

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Example

11 is a term since it is a prime and 42*11 - 1 = 461 and 42*11 + 1 = 463 are twin primes.
31 is a term since it is a prime and 42*31 - 1 = 1301 and 42*31 + 1 = 1303 are twin primes.

Mathematica

a=42; Select[Prime[Range[10^3]], PrimeQ[a*#-1]&&PrimeQ[a*#+1]&]

Crossrefs

Cf. A001097, A001359, A006512.

Cf. A138657, A138658, A138659.

Sequence in context: A374029 A153128 A040971 * A144234 A109548 A173767

Adjacent sequences: A138653 A138654 A138655 * A138657 A138658 A138659

Keyword

nonn

Author

Vladimir Joseph Stephan Orlovsky, May 15 2008

Status

approved