A088651 a(n) = smallest number k such that rk-1 is prime for all r = 1 to n.

3, 3, 4, 6, 6, 154770, 2894220, 2894220, 407874180, 214580145780, 9448481062020, 247236503934420, 2545206711847800, 18178612369988250180, 53792264108455702830

Offset: 1

Author

Amarnath Murthy, Oct 29 2003

Keywords

• nonn

Comments

Is the sequence finite?

Examples

			a(5)=6 because 1*6-1, 2*6-1, 3*6-1, 4*6-1, 5*6-1 are all prime.
a(11)=9448481062020 because all eleven numbers 1*9448481062020-1, 2*9448481062020-1,3*9448481062020-1,...,10*9448481062020-1 & 11*9448481062020-1 are prime and 9448481062020 is the smallest number with such property.
		

Links

• Carlos Rivera, Problems & Puzzles.

Crossrefs

Cf. A088652, A125838, A125839, A088250, A101779.

Extensions

Corrected and extended by Ray Chandler, Nov 01 2003

More terms from Don Reble, Nov 23 2003

Entry revised by N. J. A. Sloane, Jan 05 2007

a(14)-a(15) from Jens Kruse Andersen, May 02 2008