Number of minimax elements in the affine Weyl group of the Lie algebra so(2n).

Terms

a(0) =1a(1) =3a(2) =4a(3) =9a(4) =23a(5) =61a(6) =166a(7) =459a(8) =1284a(9) =3623a(10) =10292a(11) =29395a(12) =84327a(13) =242807a(14) =701314a(15) =2031085a(16) =5895951a(17) =17150013a(18) =49975428a(19) =145862571a(20) =426337773a(21) =1247741271a(22) =3655973226a(23) =10723668081a(24) =31485145902a(25) =92524150845a(26) =272120203908a(27) =800931753629