The side lengths of a Heronian Triangle are R-1, R and R+1, where R is an 8-digit positive integer which does not contain any leading zero.

Determine all possible value(s) of R for which this is possible.

The wikipedia article for Equilateral Triangle has a section for Almost Equilateral Heronian Triangles with a link to the integer sequence http://www.research.att.com/~njas/sequences/A003500

This entry even gives the formula derived by Jim K.  The only 8 digit number is 27246964

Posted by Jer on 2009-11-16 15:11:19