A191145 Increasing sequence S generated by these rules: a(1)=1, and if x is in S then both 3x+2 and 4x+3 are in S.

1, 5, 7, 17, 23, 31, 53, 71, 95, 127, 161, 215, 287, 383, 485, 511, 647, 863, 1151, 1457, 1535, 1943, 2047, 2591, 3455, 4373, 4607, 5831, 6143, 7775, 8191, 10367, 13121, 13823, 17495, 18431, 23327, 24575, 31103, 32767, 39365, 41471, 52487, 55295, 69983, 73727, 93311, 98303, 118097, 124415, 131071, 157463, 165887

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 = 3; f = 1; g = 11;
a = Union[Flatten[NestList[{h # + i, j # + k} &, f, g]]]  (* A191145 *)
b = (a - 2)/3; c = (a - 3)/4; r = Range[1, 16000];
d = Intersection[b, r] (* A191145 *)
e = Intersection[c, r] (* A191145 *)
m = (a + 1)/2  (* A025613 *)

Prog

(Haskell)
import Data.Set (singleton, deleteFindMin, insert)
a191145 n = a191145_list !! (n-1)
a191145_list = f $ singleton 1
   where f s = m : (f $ insert (3*m+2) $ insert (4*m+3) s')
             where (m, s') = deleteFindMin s
-- Reinhard Zumkeller, Jun 01 2011

Crossrefs

See A191113.

Sequence in context: A359297 A283159 A283145 * A145354 A214345 A166109

Adjacent sequences: A191142 A191143 A191144 * A191146 A191147 A191148

Keyword

nonn

Author

Clark Kimberling, May 28 2011

Status

approved