5148297domain: NAppears in sequencesa(n) = (5*n + 4)*binomial(n+7,7)/4.at n=16A056125Denominator of Sum_{k=1..n} k^2*H_{n+k} where H_m = Sum_{i=1..m} 1/i.at n=12A144653a(n) = 21*binomial(n+6,7).at n=17A266733