A diagonal of irregular triangle A201949.

Terms

a(0) =1a(1) =1a(2) =5a(3) =24a(4) =139a(5) =945a(6) =7377a(7) =65016a(8) =638418a(9) =6910650a(10) =81747665a(11) =1049089470a(12) =14516096009a(13) =215419836359