Euler characteristics of polytopes.

Terms

a(0) =1a(1) =1a(2) =0a(3) =2a(4) =5a(5) =9a(6) =14a(7) =20a(8) =69a(9) =125a(10) =209a(11) =329a(12) =923a(13) =1715a(14) =3002a(15) =5004a(16) =12869a(17) =24309a(18) =43757a(19) =75581a(20) =184755a(21) =352715a(22) =646645a(23) =1144065a(24) =2704155a(25) =5200299a(26) =9657699a(27) =17383859a(28) =40116599