A126660 Array read by antidiagonals: A(k,n) = smallest odd prime q such that pq+2k is prime, where p is the n-th odd prime, or 0 if no such prime exists.

3, 3, 3, 0, 3, 3, 3, 5, 7, 7, 3, 3, 5, 3, 3, 0, 0, 3, 5, 3, 3, 3, 5, 3, 3, 5, 5, 3, 5, 3, 5, 3, 3, 11, 3, 3, 0, 3, 0, 5, 7, 3, 5, 3, 3, 3, 5, 3, 3, 7, 3, 5, 7, 5, 5, 3, 0, 5, 5, 3, 5, 3, 13, 5, 3, 3, 0, 3, 3, 5, 7, 19, 5, 3, 7, 7, 7, 61, 5, 7, 3, 3, 5, 3, 3, 5, 3, 3, 5, 3, 3, 3, 3, 5, 0, 3, 5, 3, 3, 5, 3, 5, 5, 13

Offset

1,1

Links

Table of n, a(n) for n=1..104.

Example

Row 1 of the array is A126608 = smallest odd prime q such that pq+2 is prime, where p is the n-th odd prime.
Array with rows k and columns n starts
k\p..3...5...7..11..13..17..19..23..29..31..37..41..43..47.
-------------------
.1|..3...3...3...7...3...3...3...3...3...5...3..61...3...7.
.2|..3...3...7...3...3...5...3...3...5...3...7...3..13...5.
.3|..0...5...5...5...5..11...5...7...5...7...5...5...7...5.
.4|..3...3...3...3...3...3...5..13...7...3...5...3...3...3.
.5|..3...0...3...3...7...3...3...3...3...3...7..11...3...3.
.6|..0...5...5...5...7...5...5...5...5...5...5..11...5..17.
.7|..3...3...0...3...3..19...3...3...3...3...5...3...5..19.
.8|..5...3...3...5...7...3...3...5...3...3...3...3...7...3.
.9|..0...5...5...5...5...5...5...7...5...5...7...5...5...7.
10|..3...0...3...3...3...3..11...3...3...3...3...7...3...7.
11|..3...3...3...0...3...3...3...5...3...7...7...5...3...3.
12|..0...7...5...5...5...5...7...5...7...5...7...5...5...7.
13|..5...3...3...3...0..19...3..19...3...5...3...3...5...3.
14|..3...3...0...3...3...3..19...3...5..13...3...3...3...5.

Crossrefs

Cf. A000040, A126608-A126609, A126661.

Sequence in context: A329273 A130719 A143606 * A202698 A320785 A164884

Adjacent sequences: A126657 A126658 A126659 * A126661 A126662 A126663

Keyword

easy,nonn,tabl

Author

Jonathan Vos Post, Feb 09 2007

Extensions

Corrected and extended by R. J. Mathar, Feb 13 2007

Status

approved