69878domain: NAppears in sequencesa(n) = left term in M^n * [1 0 0], where M = the 3 X 3 matrix [1 -1 0 / -1 4 -3 / 0 -3 3].at n=8A094431Arises in combinatorial approach to the power of 2 in the number of involutions.at n=15A157253Number of ordered triples (w,x,y) with all terms in {-n,...-1,1,...,n} and 3w+x+y>0.at n=26A211628