a(n) = [x^n] x/(12*x^2 - 6*x + 1).

Terms

a(0) =0a(1) =1a(2) =6a(3) =24a(4) =72a(5) =144a(6) =0a(7) =-1728a(8) =-10368a(9) =-41472a(10) =-124416a(11) =-248832a(12) =0a(13) =2985984a(14) =17915904a(15) =71663616a(16) =214990848a(17) =429981696a(18) =0a(19) =-5159780352a(20) =-30958682112a(21) =-123834728448a(22) =-371504185344a(23) =-743008370688a(24) =0