%I A002161 M4332 N1814
%S A002161 1,7,7,2,4,5,3,8,5,0,9,0,5,5,1,6,0,2,7,2,9,8,1,6,7,4,8,3,3,4,1,1,4,5,1,
%T A002161 8,2,7,9,7,5,4,9,4,5,6,1,2,2,3,8,7,1,2,8,2,1,3,8,0,7,7,8,9,8,5,2,9,1,1,
%U A002161 2,8,4,5,9,1,0,3,2,1,8,1,3,7,4,9,5,0,6,5,6,7,3,8,5,4,4,6,6,5
%N A002161 Decimal expansion of square root of Pi.
%C A002161 Also Gamma(1/2). - Frank Adams-Watters (FrankTAW(AT)Netscape.net), Apr 
               07 2006
%C A002161 The integral of the Gaussian function Exp(-x^2) over the real line. - 
               Richard Chapling (r.chappers(AT)gmail.com), Jun 05 2008
%D A002161 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%D A002161 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 
               (includes this sequence).
%D A002161 W. E. Mansell, Tables of Natural and Common Logarithms. Royal Society 
               Mathematical Tables, Vol. 8, Cambridge Univ. Press, 1964, p. XVIII.
%H A002161 Harry J. Smith, <a href="b002161.txt">Table of n, a(n) for n=1,...,20000</
               a>
%H A002161 <a href="Sindx_Ph.html#Pi314">Index entries for sequences related to 
               the number Pi</a>
%e A002161 1.7724538509055160272981674833411451827975494561223871282138...
%t A002161 RealDigits[N[Sqrt[Pi], 120]][[1]] - Richard Chapling (r.chappers(AT)gmail.com), 
               Jun 05 2008
%o A002161 (PARI) { default(realprecision, 20080); x=sqrt(Pi); for (n=1, 20000, 
               d=floor(x); x=(x-d)*10; write("b002161.txt", n, " ", d)); } [From 
               Harry J. Smith (hjsmithh(AT)sbcglobal.net), May 01 2009]
%Y A002161 Cf. A000796.
%Y A002161 Sequence in context: A102400 A144860 A113810 this_sequence A083871 A126584 
               A021568
%Y A002161 Adjacent sequences: A002158 A002159 A002160 this_sequence A002162 A002163 
               A002164
%K A002161 nonn,cons
%O A002161 1,2
%A A002161 N. J. A. Sloane (njas(AT)research.att.com).
%E A002161 More terms from Frank Adams-Watters (FrankTAW(AT)Netscape.net), Apr 07 
               2006
%E A002161 Fixed my PARI program, had -n Harry J. Smith (hjsmithh(AT)sbcglobal.net), 
               May 19 2009