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A191140 Increasing sequence generated by these rules:  a(1)=1, and if x is in a then 3x+2 and 4x-2 are in a. 4
1, 2, 5, 6, 8, 17, 18, 20, 22, 26, 30, 53, 56, 62, 66, 68, 70, 78, 80, 86, 92, 102, 118, 161, 170, 188, 200, 206, 210, 212, 222, 236, 242, 246, 260, 262, 270, 278, 308, 310, 318, 342, 356, 366, 406, 470, 485, 512, 566, 602, 620, 632, 638, 642, 668, 678, 710, 728, 740, 750, 782, 788, 798, 812, 822, 836, 838, 846, 886, 926, 932, 942 (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 = 2; j = 4; k = -2; f = 1; g = 9;

a = Union[Flatten[NestList[{h # + i, j # + k} &, f, g]]]  (* A191140 *)

b = (a - 2)/3; c = (a + 2)/4; r = Range[1, 1500];

d = Intersection[b, r] (* A191204 *)

e = Intersection[c, r] (* A191205 *)

PROG

(Haskell)

import Data.Set (singleton, deleteFindMin, insert)

a191140 n = a191140_list !! (n-1)

a191140_list = f $ singleton 1

   where f s = m : (f $ insert (3*m+2) $ insert (4*m-2) s')

             where (m, s') = deleteFindMin s

-- Reinhard Zumkeller, Jun 01 2011

CROSSREFS

Cf. A191113.

Sequence in context: A242665 A079256 A191204 * A271430 A326854 A097685

Adjacent sequences:  A191137 A191138 A191139 * A191141 A191142 A191143

KEYWORD

nonn

AUTHOR

Clark Kimberling, May 28 2011

STATUS

approved

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Last modified September 30 12:21 EDT 2020. Contains 337439 sequences. (Running on oeis4.)