Convolution of the generalized Catalan numbers A057977 with themselves.

Terms

a(0) =1a(1) =2a(2) =3a(3) =8a(4) =11a(5) =30a(6) =43a(7) =112a(8) =172a(9) =420a(10) =694a(11) =1584a(12) =2809a(13) =6006a(14) =11379a(15) =22880a(16) =46088a(17) =87516a(18) =186562a(19) =335920a(20) =754646a(21) =1293292a(22) =3050238a(23) =4992288a(24) =12319816a(25) =19315400a(26) =49725004a(27) =74884320a(28) =200571541a(29) =290845350