Boustrophedon transform of (n+1) mod 2.

Terms

a(0) =1a(1) =1a(2) =2a(3) =5a(4) =12a(5) =41a(6) =152a(7) =685a(8) =3472a(9) =19921a(10) =126752a(11) =887765a(12) =6781632a(13) =56126201a(14) =500231552a(15) =4776869245a(16) =48656756992a(17) =526589630881