A ménage triangle.

Terms

a(0) =1a(1) =0a(2) =1a(3) =0a(4) =1a(5) =1a(6) =1a(7) =1a(8) =3a(9) =1a(10) =3a(11) =8a(12) =6a(13) =6a(14) =1a(15) =16a(16) =35a(17) =38a(18) =20a(19) =10a(20) =1a(21) =96a(22) =211a(23) =213a(24) =134a(25) =50a(26) =15a(27) =1a(28) =675a(29) =1459