A156051 Sequence of pairs k>0 and j>1 with the smallest j and the smallest sum j+k such that k*j^n-1 is prime.

2, 2, 1, 2, 1, 2, 2, 2, 1, 2, 2, 2, 1, 2, 2, 3, 2, 4, 5, 2, 3, 2, 2, 2, 1, 2, 5, 2, 4, 2, 2, 2, 1, 2, 2, 2, 1, 2, 2, 3, 7, 2, 6, 3, 2, 3, 2, 5, 4, 5, 2, 6, 2, 3, 8, 2, 4, 2, 2, 2, 1, 2, 5, 2, 6, 2, 3, 2, 2, 3, 2, 6, 6, 2, 3, 2, 4, 5, 2, 6, 3, 6, 6, 2, 3, 2, 2, 4, 4, 3, 2, 7, 3, 4, 5, 2, 2, 6, 8, 3

Offset

1,1

Comments

When k=j=2, P is a Mersenne prime 2^(n+1)-1 with n+1 prime.

Links

Table of n, a(n) for n=1..100.

David Broadhurst, The first 3000 rows

David Broadhurst, Statistics on Pierre CAMI's Riesel-hypotenuse (RH) primes, Yahoo! group "primenumbers", Feb 04 2009

David Broadhurst, Statistics on Pierre CAMI's Riesel-hypotenuse (RH) primes, Yahoo! group "primenumbers", Feb 04 2009 (local copy)

David Broadhurst, Pierre CAMI, Riesel-hypotenuse (RH) primes, digest of 11 messages in primeform Yahoo group, Feb 4, 2009 - Oct 15, 2013. [Cached copy]

Example

2*2^1-1=3 prime so first pair =2,2 as 1*2^1-1 is unity.
1*2^2-1=3 so second pair is 1,2.

Crossrefs

Sequence in context: A218775 A370558 A191971 * A091267 A003643 A092788

Adjacent sequences: A156048 A156049 A156050 * A156052 A156053 A156054

Keyword

nonn,tabf

Author

Pierre CAMI, Feb 02 2009

Status

approved