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Increasing sequence generated by these rules: a(1)=1, and if x is in a then 3x-2 and 4x are in a.
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%I #10 Jul 13 2013 12:04:09

%S 1,4,10,16,28,40,46,64,82,112,118,136,160,184,190,244,256,328,334,352,

%T 406,448,472,478,544,550,568,640,730,736,760,766,976,982,1000,1024,

%U 1054,1216,1312,1336,1342,1408,1414,1432,1624,1630,1648,1702,1792,1888,1912,1918,2176,2188,2200,2206,2272,2278,2296,2560,2920

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

%C See A191113.

%H Reinhard Zumkeller, <a href="/A191115/b191115.txt">Table of n, a(n) for n = 1..10000</a>

%t h = 3; i = -2; j = 4; k = 0; f = 1; g = 9;

%t a = Union[Flatten[NestList[{h # + i, j # + k} &, f, g]]] (* A191115 *)

%t b = (a + 2)/3; c = a/4; r = Range[1, 1500];

%t d = Intersection[b, r] (* A191113 *)

%t e = Intersection[c, r] (* A191154 *)

%t m = a/2 (* divisibility property *)

%o (Haskell)

%o import Data.Set (singleton, deleteFindMin, insert)

%o a191115 n = a191115_list !! (n-1)

%o a191115_list = 1 : f (singleton 4)

%o where f s = m : (f $ insert (3*m-2) $ insert (4*m) s')

%o where (m, s') = deleteFindMin s

%o -- _Reinhard Zumkeller_, Jun 01 2011

%Y Cf. A191113.

%K nonn

%O 1,2

%A _Clark Kimberling_, May 27 2011