Average of n-th row of A084024.

Terms

a(0) =1a(1) =33a(2) =141a(3) =2442a(4) =50205a(5) =208857a(6) =1017701a(7) =21138612a(8) =100444001a(9) =1000450010a(10) =10006102001a(11) =210016912512