G.f.: 3F2([2/9, 4/9, 5/9], [1/3, 1], 729 x).A275457G.f.: 3F2([2/9, 4/9, 5/9], [1/3, 1], 729 x).Terms a(0) =1a(1) =120a(2) =45045a(3) =21707400a(4) =11708971560External referencesoeis: A275457