T(n,n), array T as in A047060.

Terms

a(0) =1a(1) =1a(2) =2a(3) =7a(4) =23a(5) =76a(6) =278a(7) =1014a(8) =3792a(9) =14239a(10) =53516a(11) =203219a(12) =774991a(13) =2970994a(14) =11427400a(15) =44044577a(16) =170220249a(17) =659281162a(18) =2558782202a(19) =9948657480a(20) =38736609234a(21) =151032841208a(22) =589597013958