a(n) = (n!)^6 * Sum_{i=1..n} 1/i^6.A291456a(n) = (n!)^6 * Sum_{i=1..n} 1/i^6.Terms a(0) =0a(1) =1a(2) =65a(3) =47449a(4) =194397760External referencesoeis: A291456