%I #16 May 17 2019 17:18:09
%S 3,8,2,8,6,5,6,1,6,2,0,5,1,1,7,6,3,4,9,2,1,6,8,0,7,8,5,8,1,2,3,2,7,1,
%T 5,3,8,3,4,1,3,8,0,6,0,0,7,6,7,2,4,7,4,6,7,8,8,4,6,4,8,6,7,7,0,9,9,4,
%U 9,4,2,0,3,6,6,3,5,2,0,7,5,2,6,0,3,7,1,1,5,0,4,1,8,0,7,0,0,9,2,7,6,8,0,0,4
%N A continued fraction transformation of Pi.
%C The number, C, has the continued fraction which is the decimal expansion of Pi.
%e C = 3.828656162...
%t RealDigits[ FromContinuedFraction[ RealDigits[Pi, 10, 125][[1]]], 10, 111][[1]]
%o (PARI) extractDigits(x,{basis=10}) = { local(d); d=[floor(x)]; x = basis*(x - floor(x)); for (i=1,ceil(precision(x)*log(10)/log(basis))+5, d = concat(d, floor(x)); x = basis*(x - floor(x)); ); return(d); }
%o continuedFraction(digs) = { local(rtn,n,first); rtn = 0; for (i=0,#digs-1, n = digs[ #digs - i]; if (n, first = i; rtn = n; break; ); ); for (i=first+1,#digs-1, rtn = digs[ #digs - i] + 1/rtn; ); return(rtn); }
%o \p 1000
%o continuedFraction(extractDigits(Pi,10))+0. \\ Olivier Favre (of.olivier.favre(AT)gmail.com), Mar 01 2010
%Y Cf. A000796.
%K cons,easy,nonn,base
%O 1,1
%A _Robert G. Wilson v_, May 26 2004
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