Catalan numbers written backwards.

Terms

a(0) =1a(1) =1a(2) =2a(3) =5a(4) =41a(5) =24a(6) =231a(7) =924a(8) =341a(9) =2684a(10) =69761a(11) =68785a(12) =210802a(13) =9247a(14) =444762a(15) =5484969a(16) =7675353a(17) =97446921a(18) =7836774a(19) =913627671a(20) =240214656a(21) =2076266442a(22) =4636528419a(23) =56316950343