Boustrophedon transform of the signed Jacobsthal numbers.

Terms

a(0) =0a(1) =1a(2) =1a(3) =3a(4) =9a(5) =21a(6) =111a(7) =393a(8) =2309a(9) =12321a(10) =81071a(11) =560033a(12) =4301109a(13) =35526921a(14) =316858231a(15) =3025055673a(16) =30815437909a(17) =333492212321