A191134 - OEIS

%I #8 Jul 13 2013 12:04:10

%S 1,3,4,10,11,13,15,31,34,39,40,43,46,51,59,94,103,118,121,123,130,135,

%T 139,154,155,159,171,178,183,203,235,283,310,355,364,370,375,391,406,

%U 411,418,463,466,471,478,483,491,514,519,535,539,550,555,610,615,619,635,683,706,711,731,811,850,931,939,1066,1093,1111,1126

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

%C See A101113/

%H Reinhard Zumkeller, <a href="/A191134/b191134.txt">Table of n, a(n) for n = 1..10000</a>

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

%t a = Union[Flatten[NestList[{h # + i, j # + k} &, f, g]]]   (* A191134 *)

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

%t d = Intersection[b, r] (* A191192 *)

%t e = Intersection[c, r] (* A191193 *)

%o (Haskell)

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

%o a191134 n = a191134_list !! (n-1)

%o a191134_list = f $ singleton 1

%o    where f s = m : (f $ insert (3*m+1) $ insert (4*m-1) 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 28 2011