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A191123
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Increasing sequence generated by these rules: a(1)=1, and if x is in a then 3x-1 and 4x+1 are in a.
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4
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1, 2, 5, 9, 14, 21, 26, 37, 41, 57, 62, 77, 85, 105, 110, 122, 149, 165, 170, 185, 229, 230, 249, 254, 309, 314, 329, 341, 365, 421, 441, 446, 489, 494, 509, 554, 597, 661, 681, 686, 689, 741, 746, 761, 917, 921, 926, 941, 986, 997, 1017, 1022, 1094, 1237, 1257, 1262, 1317, 1322, 1337, 1365, 1461, 1466, 1481, 1526, 1661, 1685
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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 = 3; i = -1; j = 4; k = 1; f = 1; g = 9;
a = Union[Flatten[NestList[{h # + i, j # + k} &, f, g]]] (* A191123 *)
b = (a + 1)/3; c = (a - 1)/4; r = Range[1, 1500];
d = Intersection[b, r] (* A191170 *)
e = Intersection[c, r] (* A191171 *)
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PROG
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(Haskell)
import Data.Set (singleton, deleteFindMin, insert)
a191123 n = a191123_list !! (n-1)
a191123_list = f $ singleton 1
where f s = m : (f $ insert (3*m-1) $ insert (4*m+1) 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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STATUS
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approved
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