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Number of times the digit 2 appears in the first 10^n digits of Pi.
12

%I #3 Mar 30 2012 17:31:06

%S 1,12,103,1021,9908,100026,1000306,10001092,100002410,1000017271,

%T 10000026432,100000480057

%N Number of times the digit 2 appears in the first 10^n digits of Pi.

%D Alfred S. Posamentier & Ingmar Lehmann, A Biography of the World's Most Mysterious Number, Prometheus Books, Amherst, NY 2004, page 129.

%H Kanada Laboratory, <a href="http://www.super-computing.org/pi-decimal_current.html">Statistical Distribution Information</a>.

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/PiDigits.html">Pi Digits</a>

%t $MaxPrecision = 1100000; dp = Drop[ RealDigits[Pi, 10, 1000010] [[1]], 1]; Table[ Count[ Take[dp, 10^n], 2], {n, 6}]

%Y Cf. A099291, A099292, A099294, A099295, A099296, A099297, A099298, A099299, A099300.

%K nonn,base

%O 1,2

%A _Robert G. Wilson v_, Oct 11 2004