A066267 Numbers k such that A066266(k) is prime.

1, 2, 5, 12, 15, 35

Offset: 1

Author

Patrick De Geest, Dec 16 2001

Keywords

• nonn
• hard
• more

Comments

The next term, if it exists, is greater than 120. - Dmitry Kamenetsky, May 11 2009

The next term, if it exists, is greater than 400. - Michael S. Branicky, Aug 08 2024

Links

• Romeo Meštrović, Euclid's theorem on the infinitude of primes: a historical survey of its proofs (300 BC--2012) and another new proof, arXiv preprint arXiv:1202.3670 [math.HO], 2012-2023. - From N. J. A. Sloane, Jun 13 2012
• Carlos Rivera, Puzzle 118. Primorial product numbers, The Prime Puzzles & Problems Connection.
• Eric Weisstein's World of Mathematics, Primorial.

Crossrefs

Cf. A066266, A066268, A066269, A002110, A006939, A005234.

Programs

Mathematica

t={}; Do[If[PrimeQ[Times@@Table[Times@@Prime[Range[n]],{n,k}]+1],AppendTo[t,k]],{k,35}]; t (* Jayanta Basu, May 12 2013 *)

Extensions

Offset changed from 0 to 1 by Harry J. Smith, Feb 08 2010

Name simplified by Jon E. Schoenfield, Oct 25 2019