Central column of Losanitsch's triangle A034851.

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =4a(5) =6a(6) =10a(7) =19a(8) =38a(9) =66a(10) =126a(11) =236a(12) =472a(13) =868a(14) =1716a(15) =3235a(16) =6470a(17) =12190a(18) =24310a(19) =46252a(20) =92504a(21) =176484a(22) =352716a(23) =676270a(24) =1352540a(25) =2600612a(26) =5200300a(27) =10030008a(28) =20060016a(29) =38781096