47130domain: NAppears in sequencesG.f. satisfies: A(x) = A(x^2 - x^3)/(1-x).at n=40A251659Number of 6-cycles in the n-polygon diagonal intersection graph.at n=27A300554Triangle read by rows: T(n, n-k) = number of k-faces of the concertina n-cube.at n=25A300700