Number triangle associated with the Riordan arrays (1/(1+x),x/(1+x)^k),k>=0.

Terms

a(0) =1a(1) =2a(2) =1a(3) =2a(4) =2a(5) =1a(6) =2a(7) =4a(8) =2a(9) =1a(10) =2a(11) =8a(12) =6a(13) =2a(14) =1a(15) =2a(16) =16a(17) =20a(18) =8a(19) =2a(20) =1a(21) =2a(22) =32a(23) =70a(24) =38a(25) =10a(26) =2a(27) =1a(28) =2a(29) =64