This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A133375 #8 Feb 26 2015 17:18:32 %S A133375 1,1,2,5,14,24,123,249,134,2468,16679,56788,1228,2479,244467,4456899, %T A133375 3355677,12446799,3467778,112366779,12244566,222446667,1234456689, %U A133375 1333455669,112234447899 %N A133375 Catalan numbers with digits sorted in increasing order and zeros suppressed. %C A133375 This is to A000108 as A135374 is to A000225 and as A078726 is to A000215. Of the values through a(24), the only primes are the two prime Catalan numbers 2 and 5. What is the first prime in this sequence which is not an untransformed Catalan number? %F A133375 A004185(A000108(n)) = A004185((2n)!/(n!(n+1)!)). %t A133375 FromDigits[Sort[IntegerDigits[#]]]&/@CatalanNumber[Range[0,30]] (* _Harvey P. Dale_, Feb 26 2015 *) %Y A133375 Cf. A000108, A004185, A078726, A135374. %K A133375 base,easy,nonn,less %O A133375 0,3 %A A133375 _Jonathan Vos Post_, Dec 21 2007