John, Always good to hear from you. I'm sorry to ruin a good story, and I doubt if it'll make it into OEIS (but I send it to them, just in case) but the answer is probably pretty prosaic, and completely known only to the long-gone printers and binders of Academic Press in 1969. For 0 < n < 10, n+ appears on page 32n-43 n* ,, ,, 32n-35 except that 1+ doesn't appear page -11 = i (the flyleaf). Note that page -3 = ix. The pattern continues through 10 & 11, except that 10 appears only once, without star or plus. Incidentally, my copy was the complementary copy sent by Mordell to Davenport, which I obtained at DPMMS in Cambridge because Davenport had recently departed. I used to tease Mordell, because, when I was in Haifa in 1970, a suitcase was stolen from our Volkswagen van during a period of bombings. The suspicious suitcase was found in some bushes by the bomb squad. The only thing missing was a silk shirt that Louise had made for me. Mordell's book was still there, obviously of little value. Best to all, R. On Wed, 22 Aug 2007, jdb@math.arizona.edu wrote:
Dear Richard, I wonder if you know about the mysterious markings at the bottom of certain pages of Mordell's Diophantine Equations book. If one (or more) looks (look) on pages 29, 53, 61, 85, 93, 117, etc.., one (etc.) sees mysterious numbers like 5^+ or 3^* and one (etc.) wonders what in the damn hell they mean, i.e., some of us.
Since they increase as the book proceeds, it may be realted somehow to printing. Andrew Bremner thinks they may be a rock climbing code, but is unwilling to die for this idea. To be sure, Mordell was a rock climber.
Do you know right of if this was a mysterious message to readers in the know?
Best, John