Array A147985 (Polynomial coefficients) with zeros deleted.

Terms

a(0) =1a(1) =1a(2) =-1a(3) =1a(4) =-3a(5) =1a(6) =1a(7) =-7a(8) =13a(9) =-7a(10) =1a(11) =1a(12) =-15a(13) =83a(14) =-220a(15) =303a(16) =-220a(17) =83a(18) =-15a(19) =1a(20) =1a(21) =-31a(22) =413a(23) =-3141a(24) =15261a(25) =-50187a(26) =115410a(27) =-189036a(28) =222621a(29) =-189036