80624domain: NAppears in sequencesa(0) = 0, a(1) = 1, a(2*n) = n*a(2*n-1) + a(2*n-2), a(2*n+1) = a(2*n) + a(2*n-1).at n=14A056921Number of ordered triples (w,x,y) with all terms in {-n,...-1,1,...,n} and w^2>x^2+y^2.at n=34A211631