First numerator and then denominator of central elements of 1/2-Pascal triangle.

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =3a(5) =1a(6) =11a(7) =1a(8) =40a(9) =1a(10) =147a(11) =1a(12) =546a(13) =1a(14) =2046a(15) =1a(16) =7722a(17) =1a(18) =29315a(19) =1a(20) =111826a(21) =1a(22) =428298a(23) =1a(24) =1646008a(25) =1a(26) =6344366a(27) =1a(28) =24515700a(29) =1