A191120 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, 5, 6, 14, 17, 18, 22, 41, 50, 53, 54, 65, 66, 70, 86, 122, 149, 158, 161, 162, 194, 197, 198, 209, 210, 214, 257, 258, 262, 278, 342, 365, 446, 473, 482, 485, 486, 581, 590, 593, 594, 626, 629, 630, 641, 642, 646, 770, 773, 774, 785, 786, 790, 833, 834, 838, 854, 1025, 1026, 1030, 1046, 1094, 1110, 1337, 1366, 1418, 1445

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]]]  (* A191120 *)
b = (a + 1)/3; c = (a + 2)/4; r = Range[1, 1500];
d = Intersection[b, r] (* A191229 *)
e = Intersection[c, r] (* A191165 *)

Prog

(Haskell)
import Data.Set (singleton, deleteFindMin, insert)
a191120 n = a191120_list !! (n-1)
a191120_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, A191229, A191165.

Sequence in context: A083097 A215147 A191229 * A245540 A211369 A006596

Adjacent sequences: A191117 A191118 A191119 * A191121 A191122 A191123

Keyword

nonn

Author

Clark Kimberling, May 27 2011

Status

approved