Number of square rooted trees with n nodes.

Terms

a(0) =1a(1) =0a(2) =1a(3) =0a(4) =3a(5) =2a(6) =11a(7) =17a(8) =55a(9) =107a(10) =317a(11) =720a(12) =1938a(13) =4803a(14) =12707a(15) =32311a(16) =85168a(17) =220879a(18) =581112a(19) =1522095a(20) =4014186a(21) =10568936a(22) =27934075a(23) =73826753a(24) =195497427a(25) =517927859a(26) =1373858931a(27) =3646158317a(28) =9684878325a(29) =25737819213