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A190808 Increasing sequence generated by these rules:  a(1)=1, and if x is in a then 2x and 3x+1 are in a. 5
1, 2, 4, 7, 8, 13, 14, 16, 22, 25, 26, 28, 32, 40, 43, 44, 49, 50, 52, 56, 64, 67, 76, 79, 80, 85, 86, 88, 97, 98, 100, 104, 112, 121, 128, 130, 133, 134, 148, 151, 152, 157, 158, 160, 169, 170, 172, 176, 193, 194, 196, 200, 202, 208, 224, 229, 238, 241, 242, 256 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

See A190803.

LINKS

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

MATHEMATICA

h = 2; i = 0; j = 3; k = 1; f = 1; g = 9 ;

a = Union[Flatten[NestList[{h # + i, j # + k} &, f, g]]]  (* A190808 *)

b = a/2; c = (a - 1)/3; r = Range[1, 900];

d = Intersection[b, r] (* A190851 *)

e = Intersection[c, r] (* A190852 *)

PROG

(Haskell)

import Data.Set (singleton, deleteFindMin, insert)

a190808 n = a190808_list !! (n-1)

a190808_list = f $ singleton 1

   where f s = m : (f $ insert (2*m) $ insert (3*m+1) s')

             where (m, s') = deleteFindMin s

-- Reinhard Zumkeller, Jun 01 2011

CROSSREFS

Cf. A190803, A190851, A190852.

Sequence in context: A236217 A320628 A260488 * A018614 A176745 A287208

Adjacent sequences:  A190805 A190806 A190807 * A190809 A190810 A190811

KEYWORD

nonn

AUTHOR

Clark Kimberling, May 20 2011

EXTENSIONS

a(55)=224 inserted by Reinhard Zumkeller, Jun 01 2011

STATUS

approved

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Last modified July 31 10:51 EDT 2021. Contains 346373 sequences. (Running on oeis4.)