A191110 - OEIS

A191110

Increasing sequence generated by these rules: a(1)=1, and if x is in a then 3x and 3x+2 are in a.

1, 3, 5, 9, 11, 15, 17, 27, 29, 33, 35, 45, 47, 51, 53, 81, 83, 87, 89, 99, 101, 105, 107, 135, 137, 141, 143, 153, 155, 159, 161, 243, 245, 249, 251, 261, 263, 267, 269, 297, 299, 303, 305, 315, 317, 321, 323, 405, 407, 411, 413, 423, 425, 429, 431, 459, 461, 465, 467, 477, 479, 483, 485, 729, 731, 735, 737, 747, 749, 753, 755, 783

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OFFSET

1,2

COMMENTS

See discussions at A190803, A191106. A191110 has closure properties: the positive integers in (A191110)/3 form A191110, and likewise for (-2+A191110).

LINKS

Ivan Neretin, Table of n, a(n) for n = 1..10000

MATHEMATICA

h = 3; i = 0; j = 3; k = 2; f = 1; g = 7;

a = Union[Flatten[NestList[{h # + i, j # + k} &, f, g]]] (* A191110 *)

b = a/3; c = (a - 2)/3; r = Range[0, 900];

d = Intersection[b, r] (* A191110 closure property *)

e = Intersection[c, r] (* A191110 closure property *)

Flatten[Nest[{#, 3#, 3#+2}&/@#&, {1}, 6]]//Union (* Harvey P. Dale, Sep 30 2019 *)

CROSSREFS

Cf. A190803, A191106.

Sequence in context: A319985 A064988 A166699 * A178443 A287421 A214214

Adjacent sequences: A191107 A191108 A191109 * A191111 A191112 A191113

KEYWORD

nonn

AUTHOR

Clark Kimberling, May 26 2011

STATUS

approved