|Journal of Integer Sequences, Vol. 9 (2006), Article 06.3.1|
Abstract: In this paper we present some combinatorial structures enumerated by the sequence A079500 in Sloane's Encyclopedia of Integer Sequences and determine simple bijections among these structures. Then we investigate the nature of the generating function of the sequence, and prove that it is not differentiably finite.
(Concerned with sequences A002450 A048888 A057892 A067139 A067150 A067398 A067399 and A079500 .)
Received January 11 2006; revised version received July 19 2006. Published in Journal of Integer Sequences July 19 2006.