G.f.: Product_{k>0} (1 - x^k)^4 * (1 - (-x)^k)^8.

Terms

a(0) =1a(1) =4a(2) =-10a(3) =-56a(4) =29a(5) =332a(6) =30a(7) =-1064a(8) =-302a(9) =1940a(10) =288a(11) =-1960a(12) =1071a(13) =1192a(14) =-1938a(15) =-736a(16) =-2000a(17) =-1488a(18) =5014a(19) =7288a(20) =4170a(21) =-10644a(22) =-8482a(23) =11184a(24) =-12647a(25) =-15544a(26) =15590a(27) =9992a(28) =25424a(29) =4604