0,2

Stanley, R., Enumerative Combinatorics, Vol. 2, Proposition 7.10.3 and Vol. 1, Sec 3.5 Chains in Distributive Lattices.

Cf. A114717.

Adjacent sequences: A114713 A114714 A114715 this_sequence A114717 A114718 A114719

Sequence in context: A114428 A074799 A067944 this_sequence A036772 A117011 A096934

nonn,hard

Mitch Harris (Harris.Mitchell (AT) mgh.harvard.edu), Dec 27, 2005; corrected May 25 2006