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A191144 Increasing sequence generated by these rules: a(1)=1, and if x is in a then 3x+2 and 4x+2 are in a. 4

%I #8 Jul 13 2013 12:04:11

%S 1,5,6,17,20,22,26,53,62,68,70,80,82,90,106,161,188,206,212,214,242,

%T 248,250,272,274,282,320,322,330,362,426,485,566,620,638,644,646,728,

%U 746,752,754,818,824,826,848,850,858,962,968,970,992,994,1002,1088,1090,1098,1130,1280,1282,1290,1322,1450,1457,1700,1706,1862

%N 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 See A191113.

%H Reinhard Zumkeller, <a href="/A191144/b191144.txt">Table of n, a(n) for n = 1..10000</a>

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

%t a = Union[Flatten[NestList[{h # + i, j # + k} &, f, g]]] (* A191144 *)

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

%t d = Intersection[b, r] (* A191212 *)

%t e = Intersection[c, r] (* A191213 *)

%o (Haskell)

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

%o a191144 n = a191144_list !! (n-1)

%o a191144_list = f $ singleton 1

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

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Last modified April 23 23:26 EDT 2024. Contains 371917 sequences. (Running on oeis4.)