A141083 a(n) = 2^(p - 2)*(2^p - 2), where p = prime(n).

2, 12, 240, 4032, 1047552, 16773120, 4294901760, 68719214592, 17592181850112, 72057593769492480, 1152921503533105152, 4722366482800925736960, 1208925819613529663078400, 19342813113829668748787712

Offset: 1

Author

Juri-Stepan Gerasimov, Aug 05 2008

Keywords

• nonn

Examples

			Prime(1)=2, so a(1) = 2^(2 - 2)*(2^2 - 2) = 2^0*(4-2) = 2.
Prime(2)=3, so a(2) = 2^(3 - 2)*(2^3 - 2) = 2^1*(8-2) = 12.
		

Crossrefs

Cf. A020522.

Programs

Mathematica

Table[2^(n-2) (2^n-2),{n,Prime[Range[20]]}] (* Harvey P. Dale, Aug 19 2014 *)

Formula

a(n) = A020522(prime(n)-1). - Michel Marcus, Feb 18 2021

Extensions

Corrected and extended by D. S. McNeil, Mar 21 2009