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A153776
Sequence S such that 1 is in S and if x is in S, then 5x-3 and 5x-1 are in S.
2
1, 2, 4, 7, 9, 17, 19, 32, 34, 42, 44, 82, 84, 92, 94, 157, 159, 167, 169, 207, 209, 217, 219, 407, 409, 417, 419, 457, 459, 467, 469, 782, 784, 792, 794, 832, 834, 842, 844, 1032, 1034, 1042, 1044, 1082, 1084, 1092, 1094, 2032, 2034, 2042, 2044, 2082, 2084
OFFSET
1,2
COMMENTS
Subsequences include A047850, A083065.
First generation: 1
2nd generation: 2, 4
3rd generation: 7, 9, 17, 19
4th generation: 32, 34, 42, 44, 82, 84, 92, 94
Does every generation contain p or 2p for some prime p?
LINKS
MATHEMATICA
nxt[n_] := Flatten[5 # + {-3, -1} & /@ n]; Union[Flatten[NestList[nxt, {1}, 5]]] (* G. C. Greubel, Aug 28 2016 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, Jan 02 2009
STATUS
approved