A098910 Table(n,2) read by rows giving k and j such that Mersenne-prime(k) - Mersenne-prime(j) + 1 is prime.

2, 1, 3, 1, 4, 3, 5, 3, 6, 3, 7, 3, 8, 7, 8, 6, 9, 3, 10, 3, 12, 9

Offset

1,1

Links

Table of n, a(n) for n=1..22.

Example

(2^3-1)-(2^2-1)+1 = 5 = Mersenne-prime(2)-Mersenne-prime(1)+1 k=2 j=1 for n=1
(2^5-1)-(2^2-1)+1 = 29 = Mersenne-prime(3)-Mersenne-prime(1)+1 k=3 j=1 for n=2
(2^7-1)-(2^5-1)+1 = 97 = Mersenne-prime(4)-Mersenne-prime(3)+1 k=4 j=3 for n=3
and 5,29,97 are primes

Crossrefs

Sequence in context: A075388 A036445 A289187 * A291323 A290988 A165025

Adjacent sequences: A098907 A098908 A098909 * A098911 A098912 A098913

Keyword

more,nonn,tabf

Author

Pierre CAMI, Oct 16 2004

Status

approved