Reversion of Jacobsthal numbers A001045.

Terms

a(0) =1a(1) =-1a(2) =-1a(3) =5a(4) =-3a(5) =-21a(6) =51a(7) =41a(8) =-391a(9) =407a(10) =1927a(11) =-6227a(12) =-2507a(13) =49347a(14) =-71109a(15) =-236079a(16) =966129a(17) =9519a(18) =-7408497a(19) =13685205a(20) =32079981a(21) =-167077221a(22) =60639939a(23) =1209248505a(24) =-2761755543a(25) =-4457338681a(26) =30629783831a(27) =-22124857219a(28) =-206064020315a(29) =572040039283