G.f.: Product_{m>0} 1/(1 + x^m + 2*x^(2*m) + 3*x^(3*m)).

Terms

a(0) =1a(1) =-1a(2) =-2a(3) =0a(4) =5a(5) =1a(6) =-12a(7) =-3a(8) =31a(9) =13a(10) =-64a(11) =-57a(12) =139a(13) =164a(14) =-285a(15) =-458a(16) =560a(17) =1217a(18) =-950a(19) =-3176a(20) =1396a(21) =7786a(22) =-1129a(23) =-18607a(24) =-2378a(25) =43043a(26) =17680a(27) =-96655a(28) =-67957a(29) =208061