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A320636
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Negative numbers in base -3.
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1
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12, 11, 10, 22, 21, 20, 1202, 1201, 1200, 1212, 1211, 1210, 1222, 1221, 1220, 1102, 1101, 1100, 1112, 1111, 1110, 1122, 1121, 1120, 1002, 1001, 1000, 1012, 1011, 1010, 1022, 1021, 1020, 2202, 2201, 2200, 2212, 2211, 2210, 2222, 2221, 2220, 2102, 2101, 2100, 2112
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OFFSET
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1,1
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COMMENTS
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LINKS
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EXAMPLE
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-7 in base -3 is represented as 1202 (1*(-3)^3 + 2*(-3)^2 + 2 = -7), so a(7) = 1202;
-16 in base -3 is represented as 1102 (1*(-3)^3 + 1*(-3)^2 + 2 = -16), so a(16) = 1102;
-40 in base -3 is represented as 2222 (2*(-3)^3 + 2*(-3)^2 + 2*(-3) + 2 = -99), so a(40) = 2222.
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PROG
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(PARI) A073785 = base(n, b=-3) = if(n, base(n\b, b)*10 + n%b, 0)
(Python)
if n == 0: return 0
(q, r) = divmod(n, -3)
(nn, m) = (q, r) if r >= 0 else (q+1, r+3)
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CROSSREFS
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Negative numbers in negative bases: A305238 (b=-10), A212529 (b=-2), this sequence (b=-3), A212526 (b=-4).
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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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