A054525 * A000984.

Terms

a(0) =1a(1) =1a(2) =5a(3) =18a(4) =69a(5) =245a(6) =923a(7) =3412a(8) =12864a(9) =48549a(10) =184755a(11) =705162a(12) =2704155a(13) =10399675a(14) =40116525a(15) =155114088a(16) =601080389a(17) =2333593104a(18) =9075135299a(19) =35345215162a(20) =137846527891a(21) =538257689683