a(n) = Cosh[(2 n - 1) ArcCosh[n]].A173130a(n) = Cosh[(2 n - 1) ArcCosh[n]].Terms a(0) =0a(1) =1a(2) =26a(3) =3363a(4) =937444a(5) =456335045a(6) =343904160606External referencesoeis: A173130