a(0) = a(1) = 1; a(n+2) = Sum_{k=0..n} (binomial(n,k) mod 2) * a(k).

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =2a(5) =5a(6) =3a(7) =9a(8) =7a(9) =24a(10) =8a(11) =33a(12) =17a(13) =77a(14) =27a(15) =134a(16) =66a(17) =351a(18) =67a(19) =419a(20) =135a(21) =908a(22) =204a(23) =1469a(24) =479a(25) =3643a(26) =553a(27) =4572a(28) =1182a(29) =10227