[seqfan] Re: looking for bijections

Hans Havermann pxp at rogers.com
Thu Jun 10 18:15:11 CEST 2010


Antti Karttunen:

"And of course, for a standard way of converting from binary trees to  
Dyck words, there is that caterpillar traversing the binary tree depth- 
first-wise from left to right, as presented by Martin Gardner in his  
Sci-Am 197? column. (I have the photocopies, but I have lost the copy  
of the cover, so I miss the exact year. 1976 or 1977? Wouter, do you  
remember? ;-)"

Martin Gardner's June 1976 article covered "Catalan numbers" (p. 
120-125) and had a picture of a caterpillar-like "worm crawling up the  
trunk" of a binary tree.

wouter meeussen:

"1976, september (or october), with, I believe, monkeys or apes on the  
cover, ;-))"

October 1976 had macaques on the cover. Gardner's article that month  
was on "Combinatorial problems... attacked by computer".




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