A191142 Increasing sequence generated by these rules: a(1)=1, and if x is in a then 3x+2 and 4x are in a.

1, 4, 5, 14, 16, 17, 20, 44, 50, 53, 56, 62, 64, 68, 80, 134, 152, 161, 170, 176, 188, 194, 200, 206, 212, 224, 242, 248, 256, 272, 320, 404, 458, 485, 512, 530, 536, 566, 584, 602, 608, 620, 638, 644, 674, 680, 704, 728, 746, 752, 770, 776, 800, 818, 824, 848, 896, 962, 968, 992, 1024, 1088, 1214, 1280, 1376, 1457, 1538, 1592

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 = 0; f = 1; g = 9;
a = Union[Flatten[NestList[{h # + i, j # + k} &, f, g]]]  (* A191142 *)
b = (a - 2)/3; c = a/4; r = Range[1, 1500];
d = Intersection[b, r] (* A191208 *)
e = Intersection[c, r] (* A191209 *)

Prog

(Haskell)
import Data.Set (singleton, deleteFindMin, insert)
a191142 n = a191142_list !! (n-1)
a191142_list = f $ singleton 1
   where f s = m : (f $ insert (3*m+2) $ insert (4*m) s')
             where (m, s') = deleteFindMin s
-- Reinhard Zumkeller, Jun 01 2011

Crossrefs

Cf. A191113.

Sequence in context: A008540 A290810 A000867 * A049770 A262903 A079362

Adjacent sequences: A191139 A191140 A191141 * A191143 A191144 A191145

Keyword

nonn

Author

Clark Kimberling, May 28 2011

Status

approved