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A355640
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a(0) = 0, and for any n > 0, a(n) is the least positive multiple of n whose balanced ternary expansion contains as many negative trits as positive trits.
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1
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0, 2, 2, 6, 8, 20, 6, 56, 8, 18, 20, 154, 24, 26, 56, 60, 16, 136, 18, 266, 20, 168, 154, 46, 24, 400, 26, 54, 56, 232, 60, 62, 32, 462, 136, 70, 72, 74, 266, 78, 80, 164, 168, 86, 440, 180, 46, 188, 48, 98, 400, 408, 52, 424, 54, 440, 56, 798, 232, 236, 60
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OFFSET
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0,2
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COMMENTS
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A174658 corresponds to fixed points.
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LINKS
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FORMULA
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EXAMPLE
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For n = 5:
- the first multiple of 5 (alongside their balanced ternary expansions) are:
k k*5 bter(k*5) #1 #T
- --- --------- -- --
1 5 1TT 1 2
2 10 101 2 0
3 15 1TT0 1 2
4 20 1T1T 2 2
- negative and positive trits are first balanced for k = 4,
- so a(5) = 4*5 = 20.
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PROG
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(PARI) a(n) = { for (k=1, oo, my (m=k*n, s=0, d); while (m, m=(m-d=[0, 1, -1][1+m%3])/3; s+=d); if (s==0, return (k*n))) }
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CROSSREFS
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See A143146 for a similar sequence.
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KEYWORD
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nonn,base
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AUTHOR
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STATUS
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approved
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