Sequence with a (1,-1) Somos-4 Hankel transform.

Terms

a(0) =1a(1) =0a(2) =-1a(3) =-1a(4) =-2a(5) =-6a(6) =-14a(7) =-27a(8) =-39a(9) =-4a(10) =269a(11) =1415a(12) =5258a(13) =16321a(14) =43705a(15) =98459a(16) =163216a(17) =49326a(18) =-1120684a(19) =-6502098a(20) =-25711856a(21) =-83830889a(22) =-233926105a(23) =-545916369a(24) =-932372648a(25) =-280663557a(26) =6802456973a(27) =40262637059a(28) =162298734532a(29) =538385811978