228876

Appears in sequences

• Number of nX3 -1,1 arrays such that the sum over i=1..n,j=1..3 of i*x(i,j) is zero and rows are nondecreasing (ways to put 3 thrusters pointing east or west at each of n positions 1..n distance from the hinge of a south-pointing gate without turning the gate).at n=11A225304
• Number of (not necessarily maximal) cliques in the n-polygon diagonal intersection graph.at n=35A300524