Permanent of a certain cyclic n X n (0,1) matrix.

Terms

a(0) =1a(1) =1a(2) =2a(3) =6a(4) =24a(5) =120a(6) =265a(7) =579a(8) =1265a(9) =2783a(10) =6208a(11) =13909a(12) =31337a(13) =70985a(14) =161545a(15) =369024a(16) =845825a(17) =1944295a(18) =4480285a(19) =10345391a(20) =23930320a(21) =55435605a(22) =128577253a(23) =298529333a(24) =693718721a(25) =1613210120a(26) =3753680073a(27) =8738534315a(28) =20351593033a(29) =47413960239