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A192588
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, and 8 are in S.
3
2, 3, 4, 5, 6, 7, 8, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 61, 67, 73, 101, 103, 113, 137, 151, 163, 173, 257, 281, 401, 487, 547, 617, 677, 691, 821, 823, 977, 1093, 1123, 1303, 1381, 2467, 2707, 3701, 3907, 4933, 4937, 5413, 5527, 5861, 6737, 7817
OFFSET
1,1
COMMENTS
See the discussions at A192476 and A192580.
Last term is a(61) = 62533. - Giovanni Resta, Mar 21 2013
LINKS
Giovanni Resta, Table of n, a(n) for n = 1..61 (full sequence)
MATHEMATICA
start = {2, 4, 6, 8}; 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