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%I #9 Mar 30 2012 18:39:16
%S 1,4,32,1158,1815746,15716561494212,1184500978807872650350593387,
%T 5321879016477546178356935033926215638755808624425727229,
%U 28586857373644233013728565794450100157386617152409721820238727067747604580786570816033645416762395120483912199
%N Continued cotangent for tan(1).
%D D. H. Lehmer, A cotangent analogue of continued fractions, Duke Math. J., 4 (1935), 323-340.
%F tan(1)=cot(sum(n>=0, n, (-1)^n*acot(a(n))); let b(0)=tan(1), b(n)=(b(n-1)*floor(b(n-1))+1)/(b(n-1)-floor(b(n-1)) then a(n)=floor(b(n))
%o (PARI) ?bn=vector(100); b(n)=if(n<0,0,bn[n]); bn[1]=tan(1); ?for(n=2,10,bn[n]=(b(n-1)*floor(b(n-1))+1)/(b(n-1)-floor(b(n-1)))) ?a(n)=floor(b(n+1))
%Y Cf. A002666, A002667, A002668.
%K nonn
%O 0,2
%A _Benoit Cloitre_, Apr 10 2003
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