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%I #16 Jan 03 2021 00:56:07
%S 1,1,7,7,4,1,0,0,2,2,5,1,5,4,7,4,6,9,1,0,1,1,5,6,9,3,2,6,4,5,9,6,9,9,
%T 6,3,7,7,4,7,3,8,5,6,8,9,3,8,5,8,2,0,5,3,8,5,2,2,5,2,5,7,5,6,5,0,0,0,
%U 2,6,5,8,8,5,4,6,9,8,4,9,2,6,8,0,8,4,1,8,1,3,8,3,6,8,7,7,0,8,1
%N Decimal expansion of sqrt(2*log(2)).
%C Constant arising from birthday paradox: if the year has n days, the number of people required so that the probability that at least two of them have the same birthday is 1/2 approaches 1.1774100225...*sqrt(n) for large n.
%D W. Feller, An Introduction to Probability Theory and Its Applications, Vol. 1, 2nd ed. New York: Wiley, p. 31, 1968.
%D B. Barwell, Journal of Recreational Mathematics, Soln. to Prob. 2393: "Matching Birthdays on Mars" 30(1) 71 1999-2000.
%H Harry J. Smith, <a href="/A064619/b064619.txt">Table of n, a(n) for n = 1..20000</a>
%H <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>
%e 1.1774100225...
%t RealDigits[Sqrt[2*Log[2]], 10, 50][[1]] (* _G. C. Greubel_, Sep 23 2017 *)
%o (PARI) default(realprecision, 20080); x=sqrt(2*log(2)); for (n=1, 20000, d=floor(x); x=(x-d)*10; write("b064619.txt", n, " ", d)) \\ _Harry J. Smith_, Sep 20 2009
%Y Cf. A051008.
%K cons,nonn
%O 1,3
%A Henrik Johansson (johansson.henrik(AT)home.se), Jun 06 2002