a(1) = 1; a(n) = tau(n) - tau(n-1)* a(n-1) if n > 1.

Terms

a(0) =1a(1) =1a(2) =0a(3) =3a(4) =-7a(5) =18a(6) =-70a(7) =144a(8) =-573a(9) =1723a(10) =-6890a(11) =13786a(12) =-82714a(13) =165432a(14) =-661724a(15) =2646901a(16) =-13234503a(17) =26469012a(18) =-158814070a(19) =317628146a(20) =-1905768872a(21) =7623075492a(22) =-30492301966a(23) =60984603940a(24) =-487876831517