I traded a few emails with him in the mid-1990s. The topic was ternary quadratic forms, suitably obscure. I was studying the number of representations of a number N as x^2 + y^2 + k z^2, where k = 1,2,3,... . k=2&5 have simple solutions in terms of the number of k=1 solutions for 2N or 5N. There's a more complicated rule for k=3, and k=6 has some apparent patterns. But things seem to go crazy for k=7. He'd written a paper about k=7 and 14. His message was that I was unlikely to find a pattern in these cases. Rich -----Original Message----- From: math-fun-bounces+rschroe=sandia.gov@mailman.xmission.com on behalf of Daniel Asimov Sent: Mon 7/31/2006 8:48 PM To: Daniel Asimov; math-fun Subject: Resend: [math-fun] Kaplansky's Obituary [N.B. The last link wasn't clickable since it glommed on to the right angle bracket. I hope this one works.] I don't think I saw any mention of it here, but Kaplansky passed away little over one month ago, on June 25. Here's a link to a nice obituary . . . but I wasn't able to extract specific results of his from this: http://www.signonsandiego.com/uniontrib/20060714/news_1m14kaplansk.html Actually, I'm curious -- if any cognoscenti would care to explain some theorems he's famous for, I'd be very interested. --Dan _______________________________________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun