This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A276563 #29 Feb 16 2025 08:33:36
%S A276563 1,3,4,0,7,2,7,3,8,4,6,9,7,8,7,1,2,5,0,8,0,5,6,9,8,3,7,5,4,0,5,0,8,2,
%T A276563 5,8,2,6,8,0,5,0,6,4,2,7,0,6,7,0,4,9,6,3,5,6,6,7,9,5,8,5,6,0,1,5,6,2,
%U A276563 0,6,5,9,2,1,4,8,3,3,1,9,3,8,2,6,9,9,6
%N A276563 Digits of the Leviathan number (10^666)!.
%C A276563 The factorial of 10^666, called the Leviathan number by Clifford A. Pickover, is 10^(6.655657055...*10^668), which means that it has approximately 6.656*10^668 decimal digits. The number of trailing zeros is Sum_{k=1..952} floor(10^666/5^k) = 25*10^664 - 143. The last nonzero digits are ...708672.
%D A276563 Clifford A. Pickover: Wonders of Numbers. Adventures in Mathematics, Mind, and Meaning. New York: Oxford University Press, 2001, p. 351.
%H A276563 Martin Renner, <a href="/A276563/b276563.txt">Table of n, a(n) for n = 1..984</a>
%H A276563 Robert P. Munafo, <a href="http://www.mrob.com/pub/math/numbers-22.html#lp2_b668_823"> Notable Properties of Specific Numbers - (10^666)!</a>
%H A276563 Eric W. Weisstein, <a href="https://mathworld.wolfram.com/LeviathanNumber.html">Leviathan number.</a> From MathWorld - A Wolfram Web Resource.
%Y A276563 Cf. A051003.
%K A276563 nonn,base,fini
%O A276563 1,2
%A A276563 _Martin Renner_, Nov 16 2016