A192584 Monotonic ordering of set S generated by these rules: if x and y are in S and xy+1 is a prime, then xy+1 is in S, and 2, 4, 6, 8, and 10 are in S.

2, 4, 5, 6, 8, 10, 11, 13, 17, 23, 31, 37, 41, 47, 53, 61, 67, 79, 83, 89, 101, 103, 107, 131, 137, 139, 149, 167, 179, 223, 263, 269, 283, 311, 317, 359, 367, 499, 557, 607, 619, 643, 719, 787, 809, 823, 857, 1031, 1049, 1097, 1193, 1433, 1439, 1579, 1619

Offset

1,1

Comments

See the discussions at A192580 and A192584. The number of terms in this finite sequence is 104. The greatest term is 15845273.

Links

Giovanni Resta, Table of n, a(n) for n = 1..104 (full sequence)

Mathematica

start = {2, 4, 6, 8, 10}; seq = {}; new = start; While[new != {},
seq = Union[seq, new]; fresh = new; new = {}; Do[If[PrimeQ[u = x*y + 1], If[! MemberQ[seq, u], AppendTo[new, u]]], {x, seq}, {y, fresh}]]; seq (* Giovanni Resta, Mar 21 2013 *)

Crossrefs

Cf. A192476, A192580, A192583.

Sequence in context: A330330 A189796 A284818 * A337140 A171946 A285385

Adjacent sequences: A192581 A192582 A192583 * A192585 A192586 A192587

Keyword

nonn,fini,full

Author

Clark Kimberling, Jul 04 2011

Extensions

Corrected by Giovanni Resta, Mar 21 2013

Status

approved