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A139444 Numbers n such that primorial(n)/2 - 16 is prime. 5
4, 7, 9, 13, 22, 26, 30, 33, 36, 38, 42, 114, 125, 126, 181, 291, 296, 386, 1415, 2573, 3727, 5574, 7523, 8682, 9765 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(26) > 25000. - Robert Price, Feb 25 2017

LINKS

Table of n, a(n) for n=1..25.

MATHEMATICA

k = 1; a = {}; Do[k = k*Prime[n]; If[PrimeQ[k - 16] && k>16, Print[n]; AppendTo[a, n]], {n, 2, 752}]; a

CROSSREFS

Cf. A067026, A067027, A139439-A139457, A103514.

Sequence in context: A239993 A181901 A082869 * A166569 A024608 A287111

Adjacent sequences:  A139441 A139442 A139443 * A139445 A139446 A139447

KEYWORD

nonn,more

AUTHOR

Artur Jasinski, Apr 21 2008

EXTENSIONS

Drop 2 and correct program, a(16)-a(20) from Ray Chandler, Jun 16 2013

a(21)-a(25) from Robert Price, Feb 25 2017

STATUS

approved

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Last modified August 19 08:57 EDT 2017. Contains 290794 sequences.