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A191110
Increasing sequence generated by these rules: a(1)=1, and if x is in a then 3x and 3x+2 are in a.
2
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
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
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
Sequence in context: A319985 A064988 A166699 * A178443 A287421 A214214
KEYWORD
nonn
AUTHOR
Clark Kimberling, May 26 2011
STATUS
approved