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A191140 Increasing sequence generated by these rules: a(1)=1, and if x is in a then 3x+2 and 4x-2 are in a.

%I A191140 #8 Jul 13 2013 12:04:10
%S A191140 1,2,5,6,8,17,18,20,22,26,30,53,56,62,66,68,70,78,80,86,92,102,118,
%T A191140 161,170,188,200,206,210,212,222,236,242,246,260,262,270,278,308,310,
%U A191140 318,342,356,366,406,470,485,512,566,602,620,632,638,642,668,678,710,728,740,750,782,788,798,812,822,836,838,846,886,926,932,942
%N A191140 Increasing sequence generated by these rules:  a(1)=1, and if x is in a then 3x+2 and 4x-2 are in a.
%C A191140 See A191113.
%H A191140 Reinhard Zumkeller, <a href="/A191140/b191140.txt">Table of n, a(n) for n = 1..10000</a>
%t A191140 h = 3; i = 2; j = 4; k = -2; f = 1; g = 9;
%t A191140 a = Union[Flatten[NestList[{h # + i, j # + k} &, f, g]]]  (* A191140 *)
%t A191140 b = (a - 2)/3; c = (a + 2)/4; r = Range[1, 1500];
%t A191140 d = Intersection[b, r] (* A191204 *)
%t A191140 e = Intersection[c, r] (* A191205 *)
%o A191140 (Haskell)
%o A191140 import Data.Set (singleton, deleteFindMin, insert)
%o A191140 a191140 n = a191140_list !! (n-1)
%o A191140 a191140_list = f $ singleton 1
%o A191140    where f s = m : (f $ insert (3*m+2) $ insert (4*m-2) s')
%o A191140              where (m, s') = deleteFindMin s
%o A191140 -- _Reinhard Zumkeller_, Jun 01 2011
%Y A191140 Cf. A191113.
%K A191140 nonn
%O A191140 1,2
%A A191140 _Clark Kimberling_, May 28 2011