1. An earlier reference for the Bell's triangle than Aitken, 1933 is C.S.
Peirce, American J. of Mathematics 3 (1880), p. 48. (This
was found by D. Knuth, see Pre-fascicle 3b of Volume 4 of TAOCP.)
2. The correct asymptotics of the ratio of two consecutive Bell
numbers is bn-1/bn ~ log(n)/n.
Last modified: March 2004.