209609235domain: NAppears in sequencesa(n) = [x^n] Product_{k=1..2*n} 1/(1 - k^2 * x).at n=4A348081a(n) = Sum_{l=1..n} Sum_{k=1..l} Sum_{j=1..k} Sum_{i=1..j} (l*k*j*i)^2.at n=8A353021