Mathfun'ers, Ed Pegg: Long ago, Ed Pegg sought an "interesting semiprime". I pestered him briefly, to explain what he meant by "interesting". He never explained it, but all the while, I believed that I knew what he meant: An Interesting SemiPrime (ISP) is a number which - is the product of two primes; - one has a concise proof that it's the product of two primes; and - there is scant hope of finding a proper factor. (Never mind, that "concise" is subjective and "scant hope" is temporary.) I think I found such an ISP; see http://www.graysage.com/djr/isp.txt for the rest of this message. -- Don Reble djr@nk.ca