9153731domain: NAppears in sequencesa(n) = Sum_{k=0..n} 5^k * binomial(n,k) * binomial(n+1,k).at n=7A388061a(n) = numerator(b(n)), where b(n) = b(n-1) + n if n is odd and b(n-1)*n/(b(n-1) + n) if n is even, with b(0) = 0.at n=15A392570