Triangle T(n,k) = coefficient of x^n in expansion of ((1 -sqrt(1 - 4*x - 4*x^2))/2)^k.

Terms

a(0) =1a(1) =2a(2) =1a(3) =4a(4) =4a(5) =1a(6) =12a(7) =12a(8) =6a(9) =1a(10) =40a(11) =40a(12) =24a(13) =8a(14) =1a(15) =144a(16) =144a(17) =92a(18) =40a(19) =10a(20) =1a(21) =544a(22) =544a(23) =360a(24) =176a(25) =60a(26) =12a(27) =1a(28) =2128a(29) =2128