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A139462 a(n) = m such that product n successive odd primes - 2*prime(n+m+1) is prime = such m that primorial(n+1)/2 - 2*prime(n+m+1) is prime. 4
1, 2, 1, 1, 3, 1, 2, 2, 3, 1, 6, 5, 5, 7, 1, 5, 8, 2, 10, 29, 3, 7, 10, 8, 33, 28, 11, 3, 19, 5, 12, 12, 11, 19, 52, 29, 17, 23, 29, 36, 3, 1, 7, 59, 16, 5, 4, 113, 1, 8, 16, 25, 4, 5, 52, 1, 82, 71, 14, 34, 20, 3, 1, 35, 20, 107, 14, 38, 41, 34, 14, 6, 20, 36, 36, 20, 62, 19, 8, 92, 140 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

When 1 occured in this sequence see A139463

MATHEMATICA

k = 1; a = {}; Do[k = k*Prime[n]; m = 1; While[ ! PrimeQ[k - 2*Prime[n + m]], m++ ]; Print[m]; AppendTo[a, m], {n, 2, 200}]; a (*Artur Jasinski*)

CROSSREFS

Cf. A067026, A067027, A139439, A139440, A139441, A139442, A139443, A139444, A139445, A139446, A139447, A139448, A139449, A139450, A139451, A139452, A139453, A139454, A139455, A139456, A139457, A103514, A139460, A139461, A139462, A139463.

Sequence in context: A115758 A124734 A037034 * A131376 A025840 A188542

Adjacent sequences:  A139459 A139460 A139461 * A139463 A139464 A139465

KEYWORD

nonn

AUTHOR

Artur Jasinski (grafix(AT)csl.pl), Apr 22 2008

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Last modified February 16 07:39 EST 2012. Contains 205881 sequences.