Boustrophedon transform of ((-2)^n+0^n)/2.

Terms

a(0) =1a(1) =0a(2) =1a(3) =1a(4) =1a(5) =15a(6) =11a(7) =201a(8) =561a(9) =4575a(10) =25171a(11) =187801a(12) =1400521a(13) =11694735a(14) =103903931a(15) =993285801a(16) =10113814881a(17) =109470594495