%I A145550
%S A145550 1,1,2,4,9,20,48,115,286,719,1842,4766,12486,32972,87807,235365,634792,
%T A145550 1720976,4688090,12824381,35216108,97037603,268229329,743562936,
%U A145550 2066686470,5758171390,16079351152
%N A145550 Number of distinct values taken by 10^10^...^10 (with n 10's and parentheses 
               inserted in all possible ways).
%D A145550 R. K. Guy and J. L. Selfridge, The nesting and roosting habits of the 
               laddered parenthesis. Amer. Math. Monthly 80 (1973), 868-876.
%H A145550 <a href="Sindx_Par.html#parens">Index entries for sequences related to 
               parenthesizing</a>
%Y A145550 Cf. A002845, A003018, A003019, A145545, A145546, A145547, A145548, A145549, 
               A000081.
%Y A145550 Sequence in context: A123467 A145548 A145549 this_sequence A000081 A124497 
               A093637
%Y A145550 Adjacent sequences: A145547 A145548 A145549 this_sequence A145551 A145552 
               A145553
%K A145550 more,nonn
%O A145550 1,3
%A A145550 Jon E. Schoenfield (jonscho(AT)hiwaay.net), Oct 13 2008