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%I #18 Jul 23 2018 09:52:56
%S 2,3,4,6,4,3,3,4,3,3,4,5,6,7,6,5,6,6,5,4,7,8,9,11,9,8,8,9,8,6,8,9,10,
%T 12,10,9,9,10,9,8,10,11,12,14,12,11,11,12,11,9,11,12,13,15,13,12,12,
%U 13,12,8,10,11,12,14,12,11,11,12,11,7,9,10,11,13,11,10,10,11,10,8,10,11
%N Number of letters in n-th Catalan number.
%D J. Gili, Catalan Grammar, Dolphin. Oxford 1993, p. 39.
%D R. P. Stanley, Enumerative Combinatorics, vol. 2, problem 6.24.
%H Amer. Math. Monthly 103 (1996), see pages <a href="https://www.jstor.org/stable/2974663">538</a> and <a href="https://www.jstor.org/stable/2974667">577</a>.
%H Catalan Institute of America, <a href="http://www.friendsofcatalonia.com">Home Page</a>
%H <a href="/index/Lc#letters">Index entries for sequences related to number of letters in n</a>
%e In Catalan: un, dos, tres, quatre, cinc, sis, set, vuit, nou, deu, onze, dotze, tretze, catorze, quinze, setze, disset, divuit, dinou, vint, ...
%Y Cf. A000108, A005589.
%K nonn,easy,word,nice
%O 1,1
%A _N. J. A. Sloane_ and Richard Borcherds, Dec 09 1999
%E More terms from F. Xavier Noria (fxn(AT)retemail.es) and Manuel Valdivia Prades (mvaldivia(AT)ugr.es), Dec 10 1999