A class of polytopal spheres.

Terms

a(0) =0a(1) =0a(2) =1a(3) =0a(4) =1a(5) =1a(6) =4a(7) =6a(8) =16a(9) =25a(10) =52a(11) =89a(12) =175a(13) =308a(14) =593a(15) =1066a(16) =2031a(17) =3743a(18) =7124a(19) =13330a(20) =25445a(21) =48134a(22) =92160a(23) =175743a(24) =337541a(25) =647269a(26) =1246802a(27) =2400776a(28) =4636319a(29) =8955984