A191116 Increasing sequence generated by these rules: a(1)=1, and if x is in a then 3x-2 and 4x+1 are in a.

1, 5, 13, 21, 37, 53, 61, 85, 109, 149, 157, 181, 213, 245, 253, 325, 341, 437, 445, 469, 541, 597, 629, 637, 725, 733, 757, 853, 973, 981, 1013, 1021, 1301, 1309, 1333, 1365, 1405, 1621, 1749, 1781, 1789, 1877, 1885, 1909, 2165, 2173, 2197, 2269, 2389, 2517, 2549, 2557, 2901, 2917, 2933, 2941, 3029, 3037, 3061, 3413

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 = 1; f = 1; g = 9;
a = Union[Flatten[NestList[{h # + i, j # + k} &, f, g]]]  (* A191116 *)
b = (a + 2)/3; c = (a - 1)/4; r = Range[1, 1500];
d = Intersection[b, r] (* A191155 *)
e = Intersection[c, r] (* A191129 *)
m = (a + 1)/2  (* divisibility property *)
p = (a + 3)/4  (* divisibility property *)
q = (a + 3)/8  (* divisibility property *)

Prog

(Haskell)
import Data.Set (singleton, deleteFindMin, insert)
a191116 n = a191116_list !! (n-1)
a191116_list = 1 : f (singleton 5)
   where f s = m : (f $ insert (3*m-2) $ insert (4*m+1) s')
             where (m, s') = deleteFindMin s
-- Reinhard Zumkeller, Jun 01 2011

Crossrefs

Cf. A191113.

Sequence in context: A252296 A273569 A273750 * A166051 A160170 A277189

Adjacent sequences: A191113 A191114 A191115 * A191117 A191118 A191119

Keyword

nonn

Author

Clark Kimberling, May 27 2011

Status

approved