a(n) = Sum_{k=0..n} binomial(n,k^2).

Terms

a(0) =1a(1) =2a(2) =3a(3) =4a(4) =6a(5) =11a(6) =22a(7) =43a(8) =79a(9) =137a(10) =231a(11) =397a(12) =728a(13) =1444a(14) =3018a(15) =6386a(16) =13278a(17) =26725a(18) =51852a(19) =97243a(20) =177671a(21) =320286a(22) =579371a(23) =1071226a(24) =2053626a(25) =4098627a(26) =8451288a(27) =17742649a(28) =37352435a(29) =77926452