A191137 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, 4, 6, 13, 18, 19, 26, 40, 54, 55, 58, 74, 78, 79, 106, 121, 162, 163, 166, 175, 218, 222, 223, 234, 235, 238, 298, 314, 318, 319, 364, 426, 486, 487, 490, 499, 526, 650, 654, 655, 666, 667, 670, 702, 703, 706, 715, 874, 890, 894, 895, 938, 942, 943, 954, 955, 958, 1093, 1194, 1258, 1274, 1278, 1279, 1458, 1459, 1462, 1471

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]]]   (* A191137 *)
b = (a - 1)/3; c = (a - 2)/4; r = Range[1, 1500];
d = Intersection[b, r] (* A191198 *)
e = Intersection[c, r] (* A191199 *)

Prog

(Haskell)
import Data.Set (singleton, deleteFindMin, insert)
a191137 n = a191137_list !! (n-1)
a191137_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: A063186 A345984 A191198 * A247284 A069061 A373945

Adjacent sequences: A191134 A191135 A191136 * A191138 A191139 A191140

Keyword

nonn

Author

Clark Kimberling, May 28 2011

Status

approved