Sum n^k, k=0..n+1.A173468Sum n^k, k=0..n+1.Terms a(0) =3a(1) =15a(2) =121a(3) =1365a(4) =19531a(5) =335923a(6) =6725601a(7) =153391689a(8) =3922632451a(9) =111111111111External referencesoeis: A173468