a(n) = floor(A140657(n+2)/10).

Terms

a(0) =0a(1) =0a(2) =1a(3) =2a(4) =6a(5) =12a(6) =25a(7) =50a(8) =102a(9) =204a(10) =409a(11) =818a(12) =1638a(13) =3276a(14) =6553a(15) =13106a(16) =26214a(17) =52428a(18) =104857a(19) =209714a(20) =419430a(21) =838860a(22) =1677721a(23) =3355442a(24) =6710886a(25) =13421772a(26) =26843545a(27) =53687090a(28) =107374182a(29) =214748364