a(n) = Product_{j=1..n, k=1..n} (j^4 + k^4 + n^4).A368721a(n) = Product_{j=1..n, k=1..n} (j^4 + k^4 + n^4).Terms a(0) =1a(1) =3a(2) =940896External referencesoeis: A368721