A191133 Increasing sequence generated by these rules: a(1)=1, and if x is in a then 3x+1 and 4x-2 are in a.

1, 2, 4, 6, 7, 13, 14, 19, 22, 26, 40, 43, 50, 54, 58, 67, 74, 79, 86, 102, 121, 130, 151, 158, 163, 170, 175, 198, 202, 214, 223, 230, 238, 259, 266, 294, 307, 314, 342, 364, 391, 406, 454, 475, 482, 490, 511, 518, 526, 595, 602, 607, 630, 643, 650, 670, 678, 691, 698, 715, 778, 790, 799, 806, 854, 883, 890, 918, 922, 943, 950

Offset

1,2

Comments

See A191113.

Links

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

Mathematica

h = 3; i = 1; j = 4; k = -2; f = 1; g = 9;
a = Union[Flatten[NestList[{h # + i, j # + k} &, f, g]]]   (* A191133 *)
b = (a - 1)/3; c = (a + 2)/4; r = Range[1, 1500];
d = Intersection[b, r] (* A191190 *)
e = Intersection[c, r] (* A191191 *)

Prog

(Haskell)
import Data.Set (singleton, deleteFindMin, insert)
a191133 n = a191133_list !! (n-1)
a191133_list = f $ singleton 1
   where f s = m : (f $ insert (3*m+1) $ insert (4*m-2) s')
             where (m, s') = deleteFindMin s
-- Reinhard Zumkeller, Jun 01 2011

Crossrefs

Cf. A191113.

Sequence in context: A272589 A191191 A191190 * A050053 A272634 A084591

Adjacent sequences: A191130 A191131 A191132 * A191134 A191135 A191136

Keyword

nonn

Author

Clark Kimberling, May 27 2011

Status

approved