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 A138656 Primes p such that 42*p - 1 and 42*p + 1 are twin primes. 3
 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 (list; graph; refs; listen; history; text; internal format)
 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: A061599 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

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Last modified October 4 19:37 EDT 2023. Contains 365888 sequences. (Running on oeis4.)