Invitation: celebrating 50 years of OEIS, 250000 sequences, and Sloane's 75th, there will be a conference at DIMACS, Rutgers, Oct 9-10 2014.
Table of n, a(n) for n=0..36.
S. Heubach and T. Mansour, Enumeration of 3-letter patterns in combinations
The Heubach/Mansour paper has a complicated g.f.
Sequence in context: A085489 A101268 A188920 * A235607 A001036 A054150
Adjacent sequences: A128765 A128766 A128767 * A128769 A128770 A128771
Ralf Stephan, May 08 2007
More terms from Vladeta Jovovic, Oct 04 2007