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.

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

Offset

1,2

Comments

When 1 occured in this sequence see A139463

Links

Table of n, a(n) for n=1..81.

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: A340056 A229897 A343796 * A236256 A357217 A353595

Adjacent sequences: A139459 A139460 A139461 * A139463 A139464 A139465

Keyword

nonn

Author

Artur Jasinski, Apr 22 2008

Status

approved