A057705 Primorial primes: primes p such that p+1 is a primorial number (A002110).

5, 29, 2309, 30029, 304250263527209, 23768741896345550770650537601358309, 19361386640700823163471425054312320082662897612571563761906962414215012369856637179096947335243680669607531475629148240284399976569

Offset: 1

Author

Labos Elemer, Oct 24 2000

Keywords

• nonn
• nice

Links

• Chris K. Caldwell's The Top Twenty, Primorial.
• Romeo Mestrovic, 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. - _N. J. A. Sloane_, Jun 13 2012

Crossrefs

See A006794 and A057704 (the main entries for this sequence) for more terms.

Cf. A014545, A018239.

Cf. A002110, A010051.

Subsequence of A057588.

Programs

Haskell

a057705 n = a057705_list !! (n-1)
a057705_list = filter ((== 1) . a010051) a057588_list
-- Reinhard Zumkeller, Mar 27 2013

Mathematica

Select[FoldList[Times, 1, Prime[Range[70]]], PrimeQ[# - 1] &] - 1 (* Harvey P. Dale, Jan 27 2014 *)

Formula

a(n) = A002110(A057704(n)) - 1.