3

Author

Eric W. Weisstein
October 9, 2003

This notebook downloaded from http://mathworld.wolfram.com/notebooks/Numbers/3.nb.

For more information, see Eric's MathWorld entry http://mathworld.wolfram.com/3.html.

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

3s<>1

Take[t=Table[(10^(n+1)-7)/3,{n,1,1000}],20]

Timing[Flatten[Position[%,_?PrimeQ]]-1]