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A190812 Increasing sequence generated by these rules: a(1)=1, and if x is in a then 2x+1 and 3x+2 are in a. 2

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

%S 1,3,5,7,11,15,17,23,31,35,47,53,63,71,95,107,127,143,161,191,215,255,

%T 287,323,383,431,485,511,575,647,767,863,971,1023,1151,1295,1457,1535,

%U 1727,1943,2047,2303,2591,2915,3071,3455,3887,4095,4373,4607,5183,5831,6143,6911,7775,8191,8747,9215,10367,11663

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

%C See A190803.

%H Reinhard Zumkeller, <a href="/A190812/b190812.txt">Table of n, a(n) for n = 1..10000</a>

%t h = 2; i = 1; j = 3; k = 2; f = 1; g = 20 ;

%t a = Union[Flatten[NestList[{h # + i, j # + k} &, f, g]]] (* A190812 *)

%t b = (a - 1)/2; c = (a - 2)/3; r = Range[1, 30000];

%t d = Intersection[b, r] (* A069353 *)

%t e = Intersection[c, r] (* A190812 conjectured *)

%o (Haskell)

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

%o a190812 n = a190812_list !! (n-1)

%o a190812_list = f $ singleton 1

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

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

%o -- _Reinhard Zumkeller_, Jun 01 2011

%Y Cf. A190803, A069353, A190812.

%K nonn

%O 1,2

%A _Clark Kimberling_, May 20 2011

%E a(41)=2047 inserted by _Reinhard Zumkeller_, Jun 01 2011

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Last modified July 27 20:25 EDT 2024. Contains 374651 sequences. (Running on oeis4.)