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A343317
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a(n) is the least k >= 0 such that A343316(n, k) = n.
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2
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0, 1, 4, 2, 4, 13, 11, 13, 7, 5, 7, 13, 11, 13, 40, 38, 40, 34, 32, 34, 40, 38, 40, 22, 20, 22, 16, 14, 16, 22, 20, 22, 40, 38, 40, 34, 32, 34, 40, 38, 40, 121, 119, 121, 115, 113, 115, 121, 119, 121, 103, 101, 103, 97, 95, 97, 103, 101, 103, 121, 119, 121
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OFFSET
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0,3
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COMMENTS
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To compute a(n): in the balanced ternary representation of n, replace each nonzero digit by "+1" and each nonleading zero by "-1".
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LINKS
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EXAMPLE
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The first terms, alongside their balanced ternary representation (with "T" instead of digits "-1"), are:
n a(n) bter(n) bter(a(n))
-- ---- ------- ----------
0 0 0 0
1 1 1 1
2 4 1T 11
3 2 10 1T
4 4 11 11
5 13 1TT 111
6 11 1T0 11T
7 13 1T1 111
8 7 10T 1T1
9 5 100 1TT
10 7 101 1T1
11 13 11T 111
12 11 110 11T
13 13 111 111
14 40 1TTT 1111
15 38 1TT0 111T
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PROG
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(PARI) a(n) = if (n==0, 0, my (d=centerlift(Mod(n, 3))); if (d, +1, -1) + 3*a((n-d)\3))
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CROSSREFS
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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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