Number triangle T(n,k) = Sum_{j=0..n} C(n-k,j-k)*C(j,n-j)*2^(n-j).

Terms

a(0) =1a(1) =1a(2) =1a(3) =5a(4) =3a(5) =1a(6) =13a(7) =9a(8) =5a(9) =1a(10) =49a(11) =31a(12) =17a(13) =7a(14) =1a(15) =161a(16) =105a(17) =61a(18) =29a(19) =9a(20) =1a(21) =581a(22) =371a(23) =217a(24) =111a(25) =45a(26) =11a(27) =1a(28) =2045a(29) =1313