7544041

Appears in sequences

• a(n) = P_n(9), where P_n is n-th Legendre polynomial; also, a(n) = central coefficient of (1 + 9*x + 20*x^2)^n.at n=6A084769
• P_6(2n+1), the Legendre polynomial of order 6 at 2n+1.at n=4A144126