%I #28 Jan 20 2023 22:49:54
%S 1,5,9,9,8,6,1,7,2,9,0,9,2,5,0
%N 10^n-th decimal digit of Pi.
%D David Blatner, The Joy of Pi, Walker and Co., NY, 1997; page 130 mentions the millionth digit.
%H GJ Technologies, <a href="https://web.archive.org/web/20020213073854/http://gj.mit.edu/pi/digits/">Up to 10000000 digits of Pi</a>
%H Emma Haruka Iwao, <a href="https://cloud.google.com/blog/products/compute/calculating-100-trillion-digits-of-pi-on-google-cloud">Even more pi in the sky: Calculating 100 trillion digits of pi on Google Cloud</a>
%H Yasumasa Kanada, <a href="ftp://pi.super-computing.org/.1/">6,442,450,000 decimal digits of pi and 1/pi</a> [Broken Link]
%H Aoki Mitsuru, <a href="http://www.hepl.phys.nagoya-u.ac.jp/~mitsuru/pi-e.html">Multiple digits of Pi</a> [Broken Link]
%H Steve Pagliarulo, <a href="http://members.shaw.ca/francislyster/pi/pi.html">Stu's pi page</a>
%H Daniel B. Sedory, <a href="http://thestarman.pcministry.com/math/pi/index.html">The Pi Pages</a>
%H Daniel B. Sedory, <a href="http://thestarman.pcministry.com/math/pi/PI.100.000.TXT">100,000 Decimal Digits of Pi</a>
%H Alexander J. Yee and Shigeru Kondo, <a href="http://www.numberworld.org/misc_runs/pi-10t/details.html">Round 2... 10 Trillon Digits of Pi</a>
%e 1 is the first decimal digit of Pi, 5 is the 10th decimal digit of Pi, etc.
%t Do[Print[IntegerPart[Mod[N[Pi*Floor[10^(10^n)], 10^n + 25], 10]]], {n, -1, 8}] (* _David Baugh_ *)
%Y Cf. A000796.
%K nonn,base,hard
%O 0,2
%A _Robert G. Wilson v_, Jun 30 2000
%E a(9)-a(12) from _David Baugh_, Apr 23 2004
%E a(13) from _Jason Kimberley_, Nov 08 2012
%E a(14) (using Iwao's data) from _Wolfe Padawer_, Dec 24 2022
%E Erroneous "a(-1)" term deleted and offset corrected by _Jon E. Schoenfield_, Dec 31 2022