Transform of Catalan numbers whose Hankel transform gives the Somos-4 sequence.

Terms

a(0) =1a(1) =0a(2) =1a(3) =2a(4) =6a(5) =17a(6) =51a(7) =156a(8) =488a(9) =1552a(10) =5006a(11) =16337a(12) =53849a(13) =179015a(14) =599535a(15) =2020924a(16) =6851150a(17) =23344138a(18) =79902364a(19) =274606264a(20) =947240592a(21) =3278404274a(22) =11381240074a(23) =39621423949a(24) =138288477617a(25) =483805404673