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 A267091 Primes p such that p*(2^k)+1 is also prime, where 2^k is the largest power of 2 smaller than p. 0
 2, 3, 7, 11, 53, 59, 67, 73, 109, 149, 167, 239, 277, 307, 331, 421, 433, 457, 463, 487, 563, 593, 599, 683, 719, 743, 809, 821, 929, 971, 983, 1013, 1069, 1087, 1117, 1129, 1303, 1399, 1453, 1567, 1579, 1597, 1609, 1987, 2087, 2111, 2129, 2141, 2267, 2339, 2477 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS The corresponding primes are 3, 7, 29, 89, 1697, 1889, 4289, 4673, 6977, 19073, 21377, 30593, 70913, 78593, 84737, 107777, 110849, 116993, 118529, 124673, 288257, 303617, 306689, 349697, 368129, 380417, 414209, 420353, 475649, 497153, 503297, ... LINKS EXAMPLE 3*(2^1)+1=7(is prime) => p=3, (2^k)=2; (2^k) p=11, (2^k)=8; (2^k) p=73, (2^k)=64; (2^k)

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Last modified January 18 17:18 EST 2022. Contains 350455 sequences. (Running on oeis4.)