17013984714domain: NAppears in sequencesa(n) = (1/11520) * n*(n+7)^2 * (3*n^7 + 83*n^6 + 961*n^5 + 6201*n^4 + 24708*n^3 + 60700*n^2 + 87968*n + 85056).at n=20A290723