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A191126 Increasing sequence generated by these rules:  a(1)=1, and if x is in a then 3x and 4x-3 are in a. 4
1, 3, 9, 27, 33, 81, 99, 105, 129, 243, 297, 315, 321, 387, 393, 417, 513, 729, 891, 945, 963, 969, 1161, 1179, 1185, 1251, 1257, 1281, 1539, 1545, 1569, 1665, 2049, 2187, 2673, 2835, 2889, 2907, 2913, 3483, 3537, 3555, 3561, 3753, 3771, 3777, 3843, 3849, 3873, 4617, 4635, 4641, 4707, 4713, 4737, 4995, 5001, 5025, 5121 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

See A191113.

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

MATHEMATICA

h = 3; i = 0; j = 4; k = -3; f = 1; g = 9;

a = Union[Flatten[NestList[{h # + i, j # + k} &, f, g]]]  (* A191126 *)

b = a/3; c = (a + 3)/4; r = Range[1, 1500];

d = Intersection[b, r] (* A191176 *)

e = Intersection[c, r] (* A191177 *)

m = a/3   (* divisibility property *)

p = (a + 3)/6  (* divisibility property *)

PROG

(Haskell)

import Data.Set (singleton, deleteFindMin, insert)

a191126 n = a191126_list !! (n-1)

a191126_list = 1 : f (singleton 3)

   where f s = m : (f $ insert (3*m) $ insert (4*m-3) s')

             where (m, s') = deleteFindMin s

-- Reinhard Zumkeller, Jun 01 2011

CROSSREFS

Cf. A191113.

Sequence in context: A061972 A029454 A095309 * A161141 A057238 A070364

Adjacent sequences:  A191123 A191124 A191125 * A191127 A191128 A191129

KEYWORD

nonn

AUTHOR

Clark Kimberling, May 27 2011

STATUS

approved

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Last modified August 8 23:02 EDT 2020. Contains 336300 sequences. (Running on oeis4.)