A191138 Increasing sequence generated by these rules: a(1)=1, and if x is in a then 3x+1 and 4x+3 are in a.

1, 4, 7, 13, 19, 22, 31, 40, 55, 58, 67, 79, 91, 94, 121, 127, 163, 166, 175, 202, 223, 235, 238, 271, 274, 283, 319, 364, 367, 379, 382, 487, 490, 499, 511, 526, 607, 655, 667, 670, 703, 706, 715, 811, 814, 823, 850, 895, 943, 955, 958, 1087, 1093, 1099, 1102, 1135, 1138, 1147, 1279, 1459, 1462, 1471, 1498, 1519, 1531, 1534

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 = 3; f = 1; g = 9;
a = Union[Flatten[NestList[{h # + i, j # + k} &, f, g]]]   (* A191138 *)
b = (a - 1)/3; c = (a - 3)/4; r = Range[1, 1500];
d = Intersection[b, r] (* A191200 *)
e = Intersection[c, r] (* A191201 *)

Prog

(Haskell)
import Data.Set (singleton, deleteFindMin, insert)
a191138 n = a191138_list !! (n-1)
a191138_list = f $ singleton 1
   where f s = m : (f $ insert (3*m+1) $ insert (4*m+3) s')
             where (m, s') = deleteFindMin s
-- Reinhard Zumkeller, Jun 01 2011

Crossrefs

Cf. A191113.

Sequence in context: A266811 A085787 A111710 * A075315 A238327 A243811

Adjacent sequences: A191135 A191136 A191137 * A191139 A191140 A191141

Keyword

nonn

Author

Clark Kimberling, May 28 2011

Status

approved