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A280649
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Numbers k such that k^3 has an odd number of digits and the middle digit is 9.
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12
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28, 33, 41, 108, 132, 157, 159, 175, 178, 181, 184, 187, 190, 193, 196, 204, 207, 209, 466, 474, 480, 486, 492, 508, 514, 515, 518, 519, 528, 536, 539, 552, 570, 588, 611, 627, 638, 648, 651, 657, 658, 659, 660, 706, 707, 708, 714, 719, 745, 757, 763, 765, 772
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OFFSET
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1,1
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COMMENTS
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The sequence of cubes starts: 21952, 35937, 68921, 1259712, 2299968, 3869893, 4019679, 5359375, ...
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LINKS
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EXAMPLE
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28^3 = 21(9)52, 181^3 = 592(9)741, 536^3 = 1539(9)0656.
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MATHEMATICA
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ond9Q[n_]:=Module[{idn=IntegerDigits[n^3], len}, len=Length[idn]; OddQ[len]&&idn[[(len+1)/2]]==9]; Select[Range[800], ond9Q] (* Harvey P. Dale, Mar 14 2018 *)
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CROSSREFS
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KEYWORD
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nonn,base,easy
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AUTHOR
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STATUS
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approved
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