230490domain: NAppears in sequencesa(n) = a(n-1) + 2*a(n-2) - 2*a(n-3) + a(n-5).at n=26A116157Place n points on each of the three sides of a triangle, 3n points in all; a(n) = number of nondegenerate triangles that can be constructed using these points (plus the 3 original vertices) as vertices.at n=37A130748