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A192585
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, 5, 8, 11, and 14 are in S.
2
2, 5, 8, 11, 14, 17, 23, 29, 41, 47, 59, 71, 83, 89, 113, 137, 167, 179, 197, 227, 233, 239, 359, 467, 479, 569, 659, 719, 827, 1097, 1163, 1319, 1433, 1439, 1583, 1913, 2339, 2879, 3167, 3347, 3833, 4679, 5273, 9227, 10067, 11579, 15359, 18713, 20063
OFFSET
1,1
COMMENTS
Last term is a(70) = 15785183. - Giovanni Resta, Mar 21 2013
LINKS
Giovanni Resta, Table of n, a(n) for n = 1..70 (full sequence)
MATHEMATICA
start = {2, 5, 8, 11, 14}; 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
KEYWORD
nonn,fini,full
AUTHOR
Clark Kimberling, Jul 05 2011
STATUS
approved