A175566 a(n) = the least prime p such that (2*k + 1)*p - 2*k, k=1..n are all prime.

3, 3, 7, 1171, 64591, 25153801, 25153801, 4747505071

Offset

1,1

Comments

First primes p such that (2k+1)p-2k k=1..7 are

25153801,507079861,610817971,942962791,1040241511,1223511871,1797884761.

First primes p such that (2k+1)p-2k k=1..8 are

4747505071,10817047081,21071155561,41279978041,44304317821,

49710893611,58845917971,79925475841,96466884361,106120099471,107001847261.

Links

Table of n, a(n) for n=1..8.

Crossrefs

Cf. A088878 Prime numbers p such that 3p-2 is a prime.

Sequence in context: A273043 A066142 A232459 * A349425 A248859 A171543

Adjacent sequences: A175563 A175564 A175565 * A175567 A175568 A175569

Keyword

nonn

Author

Zak Seidov, Jul 11 2010

Status

approved