This sequence needs a meaningful name.

Terms

a(0) =1a(1) =1a(2) =6a(3) =22a(4) =224a(5) =88a(6) =984a(7) =2320a(8) =10896a(9) =79296a(10) =98064a(11) =811728a(12) =2506032a(13) =14823648a(14) =109131840a(15) =59294592a(16) =495821952a(17) =1228822272a(18) =5669754624a(19) =5669754624a(20) =5669754624a(21) =5669754624a(22) =5669754624a(23) =5669754624a(24) =69265877760a(25) =132862000896