First column of triangle in A176452.

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =4a(5) =7a(6) =13a(7) =25a(8) =48a(9) =92a(10) =176a(11) =338a(12) =649a(13) =1246a(14) =2392a(15) =4594a(16) =8823a(17) =16945a(18) =32545a(19) =62509a(20) =120060a(21) =230598a(22) =442910a(23) =850701a(24) =1633948a(25) =3138339a(26) =6027842a(27) =11577747a(28) =22237515a(29) =42711863