%I A161559
%S A161559 2,11,54,136,1473,3483,36244,41086,305728,379955,582669,4540387,5020443,
%T A161559 22096761,24228660,48364856,178868536,234516235,524137295,1096104266,
%U A161559 11627672572,19828856452,31372689367,47247829739,701124643395
%N A161559 Engel expansion of tan(1/2).
%H A161559 <a href="Sindx_El.html#Engel">Index to sequences related to Engel expansions</
               a>
%e A161559 A161011 = 0.546302.... = 1/2+1/(2*11)+1/(2*11*54)+1/(2*11*54*136)+ ...
%t A161559 EngelExp[A_,n_]:=Join[Array[1&,Floor[A]],First@Transpose@NestList[{Ceiling[1/ 
               Expand[ #[[1]]#[[2]]-1]],Expand[ #[[1]]#[[2]]-1]}&,{Ceiling[1/(A-Floor[A])], 
               A-Floor[A]},n-1]]; EngelExp[N[Tan[1/2],6! ],50]
%Y A161559 Cf. A006784.
%Y A161559 Sequence in context: A052171 A030281 A063767 this_sequence A128748 A037522 
               A037731
%Y A161559 Adjacent sequences: A161556 A161557 A161558 this_sequence A161560 A161561 
               A161562
%K A161559 nonn
%O A161559 1,1
%A A161559 Vladimir Orlovsky (4vladimir(AT)gmail.com), Jun 13 2009
%E A161559 Example added by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Oct 04 
               2009