A097743 Numbers of the form 3*2^(p - 1) - 1 where p is prime.

5, 11, 47, 191, 3071, 12287, 196607, 786431, 12582911, 805306367, 3221225471, 206158430207, 3298534883327, 13194139533311, 211106232532991, 13510798882111487, 864691128455135231, 3458764513820540927

Offset: 1

Author

Parthasarathy Nambi, Sep 21 2004

Keywords

• nonn

Examples

			p=2, 2^(2-1) + (2^2 - 1) = 5;
p=3, 2^(3-1) + (2^3 - 1) = 11.
		

Links

• Iain Fox, Table of n, a(n) for n = 1..467

Crossrefs

Cf. A000396, A098102, A055010.

Programs

Mathematica

Table[3*2^(Prime[n] - 1) - 1, {n, 18}] (* Robert G. Wilson v, Sep 24 2004 *)

PARI

a(n) = 3*2^(prime(n) - 1) - 1; \\ Michel Marcus, Nov 30 2017

Formula

a(n) = A001348(n) + A061286(n). - Iain Fox, Dec 08 2017

Extensions

Edited and extended by Robert G. Wilson v, Sep 24 2004