Number of self-complementary score sequences that are possible in an n-team round-robin tournament.

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =2a(5) =5a(6) =6a(7) =15a(8) =19a(9) =48a(10) =64a(11) =161a(12) =223a(13) =557a(14) =796a(15) =1971a(16) =2887a(17) =7090a(18) =10596a(19) =25826a(20) =39256a(21) =95016a(22) =146533a(23) =352411a(24) =550328a(25) =1315827a(26) =2077418a(27) =4940587a(28) =7876036a(29) =18639221