678300

Appears in sequences

• Triangle read by rows, where the g.f. satisfies A(x, y) = 1 + x*A(x, y)^2 + x*y*A(x, y)^3.at n=40A104978
• Triangle read by rows: T(n,k) is number of paths from (0,0) to (3n,0) that stay in the first quadrant (but may touch the horizontal axis), consisting of steps u=(2,1),U=(1,2), or d=(1,-1) and have k peaks of the form Ud.at n=40A108426
• Column 2 of triangle A128545; a(n) is the coefficient of q^(2n+4) in the central q-binomial coefficient [2n+4,n+2].at n=27A128552
• Number of quadrilaterals in a triangular matchstick arrangement of side n.at n=38A204185
• a(n) = (5*n)!/((n!)^2*(3*n + 1)!).at n=4A383439