A190808 - OEIS

%I #10 Jul 13 2013 12:04:09

%S 1,2,4,7,8,13,14,16,22,25,26,28,32,40,43,44,49,50,52,56,64,67,76,79,

%T 80,85,86,88,97,98,100,104,112,121,128,130,133,134,148,151,152,157,

%U 158,160,169,170,172,176,193,194,196,200,202,208,224,229,238,241,242,256

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

%C See A190803.

%H Reinhard Zumkeller, <a href="/A190808/b190808.txt">Table of n, a(n) for n = 1..10000</a>

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

%t a = Union[Flatten[NestList[{h # + i, j # + k} &, f, g]]]  (* A190808 *)

%t b = a/2; c = (a - 1)/3; r = Range[1, 900];

%t d = Intersection[b, r] (* A190851 *)

%t e = Intersection[c, r] (* A190852 *)

%o (Haskell)

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

%o a190808 n = a190808_list !! (n-1)

%o a190808_list = f $ singleton 1

%o    where f s = m : (f $ insert (2*m) $ insert (3*m+1) s')

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

%o -- _Reinhard Zumkeller_, Jun 01 2011

%Y Cf. A190803, A190851, A190852.

%K nonn

%O 1,2

%A _Clark Kimberling_, May 20 2011

%E a(55)=224 inserted by _Reinhard Zumkeller_, Jun 01 2011