a(n) = A189912(n-1)-a(n-1) for n>0, a(0) = 1; extended Riordan numbers.

Terms

a(0) =1a(1) =0a(2) =2a(3) =2a(4) =8a(5) =17a(6) =49a(7) =128a(8) =356a(9) =983a(10) =2759a(11) =7779a(12) =22087a(13) =63000a(14) =180478a(15) =518846a(16) =1496236a(17) =4326383a(18) =12539335a(19) =36419069a(20) =105971473a(21) =308866226a(22) =901573732a(23) =2635235789a(24) =7712078755a(25) =22594899002a(26) =66266698424a(27) =194531585078a(28) =571561286576