Re: [math-fun] 2 surprising approximations and 1 exact formula for pi.

22 Jan 2011

      Hello,

  abouthe argument 2*Pi*n/163, for 500 digits
of precision I get ;

0.294129900000000000000000000000000000000000000000000000\
     0000000000000000000000000000000000000000000000000000\
     0000000000000000000000000000000000000000000000000000\
     0000000000000000000000000000000000000000000000000000\
     0000000000000000000000000000000000000000000000000000\
     0000000000000000000000000000000000000000000000000000\
     0000000000000000000000000000000000000000000000000000\
     0000000000000000000000000000000000000000000000000000\
     0000000000000000000000001153610141122787532496931945\
                                      7
     677118639979465080614285218174 10

which is almost 2941299. Are you certain that you have
enough terms in the sum ?, those series converge slowly,
n has to be 32000 to get 522 digits of precision.

  Simon Plouffe