G.f. is Q_0(q) where Q_0(q^4) is a series quadrisection of the g.f. of A161800.

Terms

a(0) =1a(1) =-6a(2) =-8a(3) =112a(4) =-86a(5) =-752a(6) =1360a(7) =1216a(8) =-5384a(9) =10762a(10) =-8176a(11) =-59888a(12) =130160a(13) =47696a(14) =-306336a(15) =485952a(16) =-632982a(17) =-1582304a(18) =4638088a(19) =343120a(20) =-6514672a(21) =8034464a(22) =-16636656a(23) =-20670528a(24) =82724176a(25) =17877578a(26) =-114481936a(27) =52539968a(28) =-178638656