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 A114466 #10 Feb 16 2025 08:32:59
%S A114466 1,5,57,598,6015,60199,602051,6020590,60205987,602059978,6020599899,
%T A114466 60205999117,602059991310,6020599913260,60205999132775,
%U A114466 602059991327940,6020599913279600,60205999132796214
%N A114466 Number of decimal digits in the 10^n-th Catalan number.
%H A114466 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/CatalanNumber.html">Catalan Number</a>
%t A114466 Table[IntegerLength[CatalanNumber[10^n]], {n, 0, 9}] (* The program generates the first 10 terms of the sequence. To generate more, increase the "9" constant but the program may take a long time to run. *) (* _Harvey P. Dale_, Sep 01 2021 *)
%Y A114466 Cf. A000108, A114493.
%K A114466 nonn,base
%O A114466 0,2
%A A114466 _Eric W. Weisstein_, Nov 29 2005
%E A114466 Edited by _Charles R Greathouse IV_, Aug 05 2010