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 A096547 Primes p such that primorial(p)/2 - 2 is prime. 5
 5, 7, 11, 13, 17, 19, 23, 31, 41, 53, 71, 103, 167, 431, 563, 673, 727, 829, 1801, 2699, 4481, 6121, 7283, 9413, 10321, 12491, 17807, 30307 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Some of the results were computed using the PrimeFormGW (PFGW) primality-testing program. - Hugo Pfoertner, Nov 14 2019 LINKS EXAMPLE a(3)=7 because primorial(7)/2 - 2 = A070826(4) - 2 = 2*3*5*7/2 - 2 = 103 is prime. MATHEMATICA k = 1; Do[k *= Prime[n]; If[PrimeQ[k - 2], Print[Prime[n]]], {n, 2, 3276}] (* Ryan Propper, Oct 25 2005 *&) CROSSREFS Cf. A070826, A096177 primes p such that primorial(p)/2+2 is prime, A096178 primes of the form primorial(p)/2+2, A014545 primorial primes, A087398. Sequence in context: A230227 A101635 A118941 * A216524 A128824 A098420 Adjacent sequences:  A096544 A096545 A096546 * A096548 A096549 A096550 KEYWORD nonn,more,hard AUTHOR Hugo Pfoertner, Jun 27 2004 EXTENSIONS 5 more terms from Ryan Propper, Oct 25 2005 STATUS approved

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Last modified July 29 09:31 EDT 2021. Contains 346344 sequences. (Running on oeis4.)