The number of people who actually got to this page (which means they not only solved the problem but clicked the link on the solution page to get here) is ...
The original puzzle came from National Public Radio's Sunday Puzzle hosted by Will Shortz .
Challenge from Jan. 1: From Ed Pegg, Jr., who runs the Web site Mathpuzzle.com: The numbers 2, 4, 6, and 30, are the first four numbers whose names lack the letter "E". What is the 23rd number whose name lacks an "E"? Answer: 2006. Winner: Mitch Berman of Witchita, Kansas. click to see NPR story
See also
to learn about "Eban" numbers (the letter "e" is banned!) from the On-Line Encyclopedia of Integer Sequences (OEIS).
I learned about all this from my friend Howard Goldstein.
The way I programmed this hinges on the fact that you can put error handlers on servers to trap specific errors. A file named .htaccess is used to define the page to run for a specific error. In this case, the file not found (code 404) error is handled by the page 2461.html which simply tells the user his entry did not qualify and provides a link back to the original form.
Here's what's in the .htaccess file:
ErrorDocument 404 http://www.primepuzzle.com/246/2461.html
The main program, 246.html, has a form on it which has an input text box named "foobar." When the user presses the Enter key the value entered in this box is passed as a parameter back to 246.html which has parameter detecting JavaScript code which issues the command
location='246'+foobar+'.html';
where foobar is the value of the number entered by the user.
This means, for example, that the page 2462030.html gets launched if the user put 2030 in the form.
There are 31 pages on the server in the 246 directory. All but 4 of them are .html files. The 4 odd balls are a .js file which is part of the command tail parameter logic, the .htaccess error handler file, a .wav file that's played when the user gets the answer and a .jpg that appears on the same answer page, 2462006.html. That leaves 27 .html files. This is one of them. 26 = 23 correct answers + 1 to handle the "answer" 2030 + 1 to handle the main program that asks for a guess (246.html) + the file 2461.html discussed above.