Oban Number

Author

Eric W. Weisstein
November 10, 2003

This notebook downloaded from http://mathworld.wolfram.com/notebooks/IntegerSequences/ObanNumber.nb.

For more information, see Eric's MathWorld entry http://mathworld.wolfram.com/ObanNumber.html.

©2005 Wolfram Research, Inc. except for portions noted otherwise

Code

ObanNumberQ[n_Integer]:=!StringMatchQ[NumberName[n],"*o*"]

Enumeration

Length[oban=Select[Range[10^4],ObanNumberQ[#]&]]//Timing

Length[oban=Select[Range[10^5],ObanNumberQ[#]&]]//Timing

Length[oban=Select[Range[10^6],ObanNumberQ[#]&]]//Timing

Take[oban,100]

Last[oban]

Plots

<<Utilities`Plot`

List Plot

ListPlot[oban,PlotStyle->Red,PlotRange->All,AxesLabel->TraditionalForm/@{n,"oban numbers"}]

Binary

Show[PixelPerfect[BasePlot[oban],BlockSize->1]]