Apply partial sum operator thrice to Catalan numbers.

Terms

a(0) =1a(1) =4a(2) =11a(3) =27a(4) =66a(5) =170a(6) =471a(7) =1398a(8) =4381a(9) =14282a(10) =47897a(11) =164012a(12) =570639a(13) =2010678a(14) =7158569a(15) =25709157a(16) =93020112a(17) =338736224a(18) =1240496193a(19) =4565563209a(20) =16878057692a(21) =62644246662a(22) =233346693759a(23) =872045012633