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

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =10a(5) =27a(6) =78a(7) =234a(8) =722a(9) =2274a(10) =7280a(11) =23617a(12) =77466a(13) =256481a(14) =856016a(15) =2876940a(16) =9728090a(17) =33072228a(18) =112974592a(19) =387580856a(20) =1334821448a(21) =4613225722a(22) =15994465796a(23) =55615889745a(24) =193904367362a(25) =677709772035