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A193992
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Position where 10^n-1 occurs in the Kaprekar sequence A006886.
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3
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2, 5, 8, 17, 24, 54, 62, 91, 102, 132, 149, 264, 281, 316, 385, 503, 527, 762, 790, 1035, 1154, 1278, 1378, 2304, 2374, 2498, 2575, 3122, 3910, 11330, 11714, 15400, 15478, 15642, 16039, 17892, 17909, 17968, 18401, 22238, 23747, 38524, 38728, 40625, 41101
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OFFSET
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1,1
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COMMENTS
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Partial sums of A194232.
The Mathematica code computes 50 terms, but only these 45 terms are correct.
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LINKS
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Hans Havermann, Table of n, a(n) for n = 1..196
Index entries for Colombian or self numbers and related sequences
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MATHEMATICA
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Inv[a_, b_] := PowerMod[a, -1, b]; t = {1}; Do[h = 10^k-1; d = Divisors[h]; d2 = Select[d, GCD[#, h/#] == 1 &]; AppendTo[t, h]; Do[AppendTo[t, d2[[i]]*Inv[d2[[i]], h/d2[[i]]]], {i, 2, Length[d2]-1}], {k, 50}]; t = Union[t]; Table[Position[t, 10^n-1, 1, 1][[1, 1]], {n, Log[10, t[[-1]]]}]
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CROSSREFS
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Cf. A006886, A194232.
Sequence in context: A216307 A176223 A006827 * A112346 A062318 A034445
Adjacent sequences: A193989 A193990 A193991 * A193993 A193994 A193995
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KEYWORD
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nonn,base
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AUTHOR
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T. D. Noe, Aug 17 2011
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STATUS
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approved
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