A074258 Gaps between primes p such that 2p-1 is also prime.

1, 4, 12, 12, 6, 42, 18, 42, 18, 42, 12, 18, 42, 36, 24, 6, 30, 12, 60, 60, 48, 30, 24, 6, 12, 42, 30, 36, 84, 18, 48, 60, 30, 30, 12, 60, 102, 66, 42, 18, 102, 30, 30, 72, 78, 18, 30, 102, 108, 144, 18, 60, 42, 6, 42, 42, 60, 30, 156, 72, 12, 6, 60, 90, 12, 72, 60

Offset

1,2

Links

Andrew Howroyd, Table of n, a(n) for n = 1..1000

Prog

(PARI) my(lsgp=2); forprime (p=3, 3000, if (isprime(2*p-1), print1(p-lsgp, ", "); lsgp=p))

Crossrefs

First differences of A005382.

Cf. A001223.

Sequence in context: A348419 A238581 A063608 * A253137 A120213 A005886

Adjacent sequences: A074255 A074256 A074257 * A074259 A074260 A074261

Keyword

nonn

Author

Jon Perry, Sep 20 2002

Extensions

Offset corrected and terms a(34) and beyond from Andrew Howroyd, Jan 16 2020

Status

approved