G.f.: x^(k^2)/(mul(1-x^(2*i),i=1..k)*mul(1+x^(2*r-1),r=1..oo)) with k=4.

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =0a(7) =0a(8) =0a(9) =0a(10) =0a(11) =0a(12) =0a(13) =0a(14) =0a(15) =0a(16) =1a(17) =-1a(18) =2a(19) =-3a(20) =5a(21) =-7a(22) =11a(23) =-15a(24) =22a(25) =-30a(26) =41a(27) =-55a(28) =74a(29) =-97