A191129 Increasing sequence generated by these rules: a(1)=1, and if x is in a then 3x and 4x+1 are in a.

1, 3, 5, 9, 13, 15, 21, 27, 37, 39, 45, 53, 61, 63, 81, 85, 109, 111, 117, 135, 149, 157, 159, 181, 183, 189, 213, 243, 245, 253, 255, 325, 327, 333, 341, 351, 405, 437, 445, 447, 469, 471, 477, 541, 543, 549, 567, 597, 629, 637, 639, 725, 729, 733, 735, 757, 759, 765, 853, 973, 975, 981, 999, 1013, 1021, 1023, 1053, 1215, 1301

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 = 1; f = 1; g = 9;
a = Union[Flatten[NestList[{h # + i, j # + k} &, f, g]]]  (* A191129 *)
b = a/3; c = (a-1)/4; r = Range[1, 1500];
d = Intersection[b, r] (* A191182 *)
e = Intersection[c, r] (* A191183 *)

Prog

(Haskell)
import Data.Set (singleton, deleteFindMin, insert)
a191129 n = a191129_list !! (n-1)
a191129_list = f $ singleton 1
   where f s = m : (f $ insert (3*m) $ insert (4*m+1) s')
             where (m, s') = deleteFindMin s
-- Reinhard Zumkeller, Jun 01 2011

Crossrefs

Cf. A191113.

Sequence in context: A187229 A089593 A204663 * A018533 A187569 A181557

Adjacent sequences: A191126 A191127 A191128 * A191130 A191131 A191132

Keyword

nonn

Author

Clark Kimberling, May 27 2011

Status

approved