a(n) = (n!)^7 * Sum_{i=1..n} 1/i^7.A291505a(n) = (n!)^7 * Sum_{i=1..n} 1/i^7.Terms a(0) =0a(1) =1a(2) =129a(3) =282251a(4) =4624680320External referencesoeis: A291505