The difference between number of even and number of odd Grassmannian permutations of size n.

Terms

a(0) =1a(1) =1a(2) =0a(3) =1a(4) =0a(5) =3a(6) =2a(7) =9a(8) =8a(9) =23a(10) =22a(11) =53a(12) =52a(13) =115a(14) =114a(15) =241a(16) =240a(17) =495a(18) =494a(19) =1005a(20) =1004a(21) =2027a(22) =2026a(23) =4073a(24) =4072a(25) =8167a(26) =8166a(27) =16357a(28) =16356a(29) =32739