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A178641 Primes p such that primorial(p)/2+2 is NOT prime. 2
11, 17, 19, 23, 41, 43, 53, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271, 277, 281, 283, 293, 311, 313, 317, 331, 337 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

3*5*7*11+2=1155=13*89, 3*5*7*11*13*17+2=255255=47*5431,..

LINKS

Table of n, a(n) for n=1..55.

MATHEMATICA

pp=1; lst={}; Do[p=Prime[n]; pp*=p; If[ !PrimeQ[pp+2], AppendTo[lst, p]], {n, 2, 2*5!}]; lst

CROSSREFS

Cf. A096177

Sequence in context: A049593 A216664 A019412 * A226682 A111257 A032677

Adjacent sequences:  A178638 A178639 A178640 * A178642 A178643 A178644

KEYWORD

nonn

AUTHOR

Vladimir Joseph Stephan Orlovsky, May 31 2010

STATUS

approved

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Last modified October 20 20:13 EDT 2019. Contains 328272 sequences. (Running on oeis4.)