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m for which p(m) is the least prime dividing #p(n) + 1, i.e., primorial n-th prime augmented by 1 (A005234).
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%I #18 Feb 19 2024 15:23:49

%S 2,4,11,47,344,17,8,69,66,67,8028643011,42,18,39,162,21,59,48,

%T 2311331257,179,369,2477,23289,32,172011,75668,342,35,28757,356411,

%U 243,297,152

%N m for which p(m) is the least prime dividing #p(n) + 1, i.e., primorial n-th prime augmented by 1 (A005234).

%C Since #P34 + 1 has two rather large factors, we need the number of primes less than or equal to 678279959005528882498681487.

%H R. Mestrovic, <a href="http://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], 2012-2018. - From N. J. A. Sloane, Jun 13 2012

%H Hisanori Mishima, <a href="http://www.asahi-net.or.jp/~KC2H-MSM/mathland/matha1/matha102.htm">Factorization results #Pn (Primorial) + 1</a>

%F a(n) = PrimePi(A051342).

%t Do[ Print[ PrimePi[ FactorInteger[ Product[ Prime[k], {k, 1, n}] + 1] [[1, 1]]]], {n, 1, 20} ]

%Y Cf. A068489.

%K nonn,hard,more

%O 1,1

%A _Lekraj Beedassy_, Mar 11 2002

%E Edited and extended by _Robert G. Wilson v_, Mar 12 2002