Square array A(n,k) = A388978(A388981(n, k)), read by descending antidiagonals.

Terms

a(0) =252a(1) =736a(2) =2640a(3) =510a(4) =6624a(5) =22512a(6) =966a(7) =4816a(8) =50400a(9) =145728a(10) =1716a(11) =8448a(12) =39072a(13) =273840a(14) =630240a(15) =14220a(16) =12064a(17) =54912a(18) =199680a(19) =975744a(20) =1799280a(21) =3744a(22) =746400a(23) =77520a(24) =279072a(25) =877200a(26) =2635776a(27) =4476096a(28) =2496a(29) =27072