Sum{T(n-k,k)}, 0<=k<=[ n/2 ], T given by A026670.

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =6a(5) =10a(6) =19a(7) =29a(8) =48a(9) =88a(10) =136a(11) =224a(12) =403a(13) =627a(14) =1030a(15) =1830a(16) =2860a(17) =4690a(18) =8257a(19) =12947a(20) =21204a(21) =37068a(22) =58272a(23) =95340a(24) =165723a(25) =261063a(26) =426786a(27) =738352a(28) =1165138a(29) =1903490