Inverse Boustrophedon transform of 2^n.

Terms

a(0) =1a(1) =1a(2) =1a(3) =0a(4) =-3a(5) =-14a(6) =-39a(7) =-130a(8) =-263a(9) =-1214a(10) =-179a(11) =-21810a(12) =98277a(13) =-1021214a(14) =8446881a(15) =-82814290a(16) =836117617a(17) =-9075846014a(18) =103898533141