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A101813
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Odd Niven (or Harshad) numbers: odd numbers that are divisible by the sum of their digits.
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1
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1, 3, 5, 7, 9, 21, 27, 45, 63, 81, 111, 117, 133, 135, 153, 171, 195, 201, 207, 209, 225, 243, 247, 261, 285, 315, 333, 351, 375, 399, 405, 407, 423, 441, 465, 481, 511, 513, 531, 555, 603, 605, 621, 629, 645, 711, 715, 735, 777, 801, 803, 825, 915, 935, 999
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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REFERENCES
| R. K. Guy, The second strong law of small numbers. Math. Mag. 63 (1990), no. 1, 3-20.
D. Wells, The Penguin Dictionary of Curious and Interesting Numbers. Penguin Books, NY, 1986, 171.
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EXAMPLE
| 629 is a term of the sequence because it is odd and divisible by 17 (=6+2+9).
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MAPLE
| s:=proc(n) local N:N:=convert(n, base, 10):sum(N[j], j=1..nops(N)) end:p:=proc(n) if floor(n/s(n))=n/s(n) then n else fi end: seq(p(2*n-1), n=1..530);
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MATHEMATICA
| Contribution from Roger L. Bagula (rlbagulatftn(AT)yahoo.com), Dec 07 2008: (Start)
a = Select[Range[1000], IntegerQ[ #/(Plus @@ IntegerDigits[ #, 10])] &];
Flatten[Table[If[IntegerQ[a[[n]]/2] == False, a[[n]], {}], {n, 1, Length[a]}]] (End)
Select[Range[1, 999, 2], Divisible[#, Total[IntegerDigits[#]]]&] (* From Harvey P. Dale, Aug 22 2011 *)
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CROSSREFS
| Cf. A005349, A101814.
Sequence in context: A030142 A179085 A076185 * A134719 A099995 A100028
Adjacent sequences: A101810 A101811 A101812 * A101814 A101815 A101816
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KEYWORD
| nonn,base
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AUTHOR
| Emeric Deutsch (deutsch(AT)duke.poly.edu), Dec 16 2004
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EXTENSIONS
| Edited by Charles R Greathouse IV (charles.greathouse(AT)case.edu), Aug 03 2010
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