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 A166530 #19 Feb 16 2025 08:33:11 %S A166530 4,7,5,0,7,7,8,7,3,0,8,2,5,1,7,7,7,2,5,4,6,3,9,2,0,9,4,8,9,0,9,7,2,6, %T A166530 6,1,8,2,1,4,4,9,1,7,1,8,0,3,9,4,7,1,3,6,6,3,1,8,7,4,7,4,0,6,3,6,8,7, %U A166530 9,2,0,0,0,0,0,0,3,0,8,4,6,4,3,2,2,1,2,9,9,8,1,1,8,0,1,8,7,9,9,6,2,0,0,0,1 %N A166530 Decimal expansion of exp(4*Pi*sqrt(163)) (or A060295^4). %C A166530 Near-integer obtained by taking Ramanujan's constant e^(Pi*sqrt(163)) to the fourth power. %D A166530 Henri Cohen, 'A Course in Computational Algebraic Number Theory', Springer-Verlag Berlin Heidelberg New-York 1996, p. 383. %H A166530 MathOverflow, <a href="http://mathoverflow.net/questions/4775/why-are-powers-of-exppisqrt163-almost-integers">Why are powers of exp(Pi*sqrt(163)) almost integers?</a> %H A166530 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/AlmostInteger.html">Almost Integer</a> %H A166530 Wikipedia, <a href="http://en.wikipedia.org/wiki/Heegner_number">Heegner number</a> %e A166530 exp^(4*Pi*sqrt(163)) = 47507787308251777254639209489097266182144917180394713663187474063... %t A166530 RealDigits[Exp[Pi Sqrt[163]]^4,10,120][[1]] (* _Harvey P. Dale_, Apr 20 2011 *) %o A166530 (PARI) exp(4*Pi*sqrt(163)) \\ _Charles R Greathouse IV_, Nov 12 2014 %Y A166530 Cf. A166528, A166529, A166531, A166532. %K A166530 nonn,cons %O A166530 70,1 %A A166530 _Mark A. Thomas_, Oct 16 2009