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A190812
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Increasing sequence generated by these rules: a(1)=1, and if x is in a then 2x+1 and 3x+2 are in a.
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2
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1, 3, 5, 7, 11, 15, 17, 23, 31, 35, 47, 53, 63, 71, 95, 107, 127, 143, 161, 191, 215, 255, 287, 323, 383, 431, 485, 511, 575, 647, 767, 863, 971, 1023, 1151, 1295, 1457, 1535, 1727, 1943, 2047, 2303, 2591, 2915, 3071, 3455, 3887, 4095, 4373, 4607, 5183, 5831, 6143, 6911, 7775, 8191, 8747, 9215, 10367, 11663
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OFFSET
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1,2
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COMMENTS
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LINKS
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MATHEMATICA
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h = 2; i = 1; j = 3; k = 2; f = 1; g = 20 ;
a = Union[Flatten[NestList[{h # + i, j # + k} &, f, g]]] (* A190812 *)
b = (a - 1)/2; c = (a - 2)/3; r = Range[1, 30000];
d = Intersection[b, r] (* A069353 *)
e = Intersection[c, r] (* A190812 conjectured *)
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PROG
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(Haskell)
import Data.Set (singleton, deleteFindMin, insert)
a190812 n = a190812_list !! (n-1)
a190812_list = f $ singleton 1
where f s = m : (f $ insert (2*m+1) $ insert (3*m+2) s')
where (m, s') = deleteFindMin s
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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