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A178648 Primes p such that primorial(p)/2 +- 2 are primes. 0
5, 7, 13, 31 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..4.

Carlos Rivera, Puzzle 974. More twins like these..., The Prime Puzzles & Problems Connection.

EXAMPLE

3*5 = 15; 15-2 and 15+2 are primes.

MATHEMATICA

pp=1; lst={}; Do[p=Prime[n]; pp*=p; If[PrimeQ[pp-2]&&PrimeQ[pp+2], Print[Date[], p]; AppendTo[lst, p]], {n, 2, 4!}]; lst

CROSSREFS

Cf. A070826, A178641, A178642.

Intersection of A096177 and A096547.

Sequence in context: A090610 A230115 A182342 * A241859 A293059 A179625

Adjacent sequences:  A178645 A178646 A178647 * A178649 A178650 A178651

KEYWORD

nonn,more

AUTHOR

Vladimir Joseph Stephan Orlovsky, May 31 2010

STATUS

approved

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Last modified November 19 03:27 EST 2019. Contains 329310 sequences. (Running on oeis4.)