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%I #41 Feb 01 2024 00:27:03
%S 5,29,2309,30029,304250263527209,23768741896345550770650537601358309,
%T 19361386640700823163471425054312320082662897612571563761906962414215012369856637179096947335243680669607531475629148240284399976569
%N Primorial primes: primes p such that p+1 is a primorial number (A002110).
%H Chris K. Caldwell's The Top Twenty, <a href="https://t5k.org/top20/page.php?id=5">Primorial</a>.
%H Romeo Mestrovic, <a href="https://arxiv.org/abs/1202.3670">Euclid's theorem on the infinitude of primes: a historical survey of its proofs (300 BC--2012) and another new proof</a>, arXiv preprint arXiv:1202.3670 [math.HO], 2012. - _N. J. A. Sloane_, Jun 13 2012
%F a(n) = A002110(A057704(n)) - 1.
%t Select[FoldList[Times, 1, Prime[Range[70]]], PrimeQ[# - 1] &] - 1 (* _Harvey P. Dale_, Jan 27 2014 *)
%o (Haskell)
%o a057705 n = a057705_list !! (n-1)
%o a057705_list = filter ((== 1) . a010051) a057588_list
%o -- _Reinhard Zumkeller_, Mar 27 2013
%Y See A006794 and A057704 (the main entries for this sequence) for more terms.
%Y Cf. A014545, A018239.
%Y Cf. A002110, A010051.
%Y Subsequence of A057588.
%K nonn,nice
%O 1,1
%A _Labos Elemer_, Oct 24 2000
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