A190812 Increasing sequence generated by these rules: a(1)=1, and if x is in a then 2x+1 and 3x+2 are in a.

1, 3, 5, 7, 11, 15, 17, 23, 31, 35, 47, 53, 63, 71, 95, 107, 127, 143, 161, 191, 215, 255, 287, 323, 383, 431, 485, 511, 575, 647, 767, 863, 971, 1023, 1151, 1295, 1457, 1535, 1727, 1943, 2047, 2303, 2591, 2915, 3071, 3455, 3887, 4095, 4373, 4607, 5183, 5831, 6143, 6911, 7775, 8191, 8747, 9215, 10367, 11663

Offset

1,2

Comments

See A190803.

Links

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Mathematica

h = 2; i = 1; j = 3; k = 2; f = 1; g = 20 ;
a = Union[Flatten[NestList[{h # + i, j # + k} &, f, g]]]  (* A190812 *)
b = (a - 1)/2; c = (a - 2)/3; r = Range[1, 30000];
d = Intersection[b, r] (* A069353 *)
e = Intersection[c, r] (* A190812 conjectured *)

Prog

(Haskell)
import Data.Set (singleton, deleteFindMin, insert)
a190812 n = a190812_list !! (n-1)
a190812_list = f $ singleton 1
   where f s = m : (f $ insert (2*m+1) $ insert (3*m+2) s')
             where (m, s') = deleteFindMin s
-- Reinhard Zumkeller, Jun 01 2011

Crossrefs

Cf. A190803, A069353, A190812.

Sequence in context: A318953 A172308 A351695 * A238738 A059748 A122124

Adjacent sequences: A190809 A190810 A190811 * A190813 A190814 A190815

Keyword

nonn

Author

Clark Kimberling, May 20 2011

Extensions

a(41)=2047 inserted by Reinhard Zumkeller, Jun 01 2011

Status

approved