A153776 Sequence S such that 1 is in S and if x is in S, then 5x-3 and 5x-1 are in S.

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

G. C. Greubel, Table of n, a(n) for n = 1..1000

Mathematica

nxt[n_] := Flatten[5 # + {-3, -1} & /@ n]; Union[Flatten[NestList[nxt, {1}, 5]]] (* G. C. Greubel, Aug 28 2016 *)

Crossrefs

Cf. A047850, A083065, A153773, A153775.

Sequence in context: A085800 A155190 A333317 * A005625 A340989 A067785

Adjacent sequences: A153773 A153774 A153775 * A153777 A153778 A153779

Keyword

nonn

Author

Clark Kimberling, Jan 02 2009

Status

approved