Catalan numbers with digits sorted in increasing order and zeros suppressed.

Terms

a(0) =1a(1) =1a(2) =2a(3) =5a(4) =14a(5) =24a(6) =123a(7) =249a(8) =134a(9) =2468a(10) =16679a(11) =56788a(12) =1228a(13) =2479a(14) =244467a(15) =4456899a(16) =3355677a(17) =12446799a(18) =3467778a(19) =112366779a(20) =12244566a(21) =222446667a(22) =1234456689a(23) =1333455669a(24) =112234447899