A191115 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, 10, 16, 28, 40, 46, 64, 82, 112, 118, 136, 160, 184, 190, 244, 256, 328, 334, 352, 406, 448, 472, 478, 544, 550, 568, 640, 730, 736, 760, 766, 976, 982, 1000, 1024, 1054, 1216, 1312, 1336, 1342, 1408, 1414, 1432, 1624, 1630, 1648, 1702, 1792, 1888, 1912, 1918, 2176, 2188, 2200, 2206, 2272, 2278, 2296, 2560, 2920

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]]]  (* A191115 *)
b = (a + 2)/3; c = a/4; r = Range[1, 1500];
d = Intersection[b, r] (* A191113 *)
e = Intersection[c, r] (* A191154 *)
m = a/2 (* divisibility property *)

Prog

(Haskell)
import Data.Set (singleton, deleteFindMin, insert)
a191115 n = a191115_list !! (n-1)
a191115_list = 1 : f (singleton 4)
   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: A036063 A112984 A343907 * A073121 A167346 A307274

Adjacent sequences: A191112 A191113 A191114 * A191116 A191117 A191118

Keyword

nonn

Author

Clark Kimberling, May 27 2011

Status

approved