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 A185280 #20 Nov 26 2024 15:17:05
%S A185280 8,8,2,5,4,2,4,0,0,6,1,0,6,0,6,3,7,3,5,8,5,8,2,5,7,2,8,4,7,1,9,9,0,7,
%T A185280 6,3,9,3,0,7,5,8,9,9,4,9,1,8,6,2,1,8,8,1,9,5,7,0,5,2,9,3,4,8,2,8,4,8,
%U A185280 7,0,6,8,1,8,6,7,4,6,7,2,9,9,9,1,9,7,2,4,4,7,4,1,5,8,7,0,2,2,3,5,5,4,5,9,3
%N A185280 Decimal expansion of a constant appearing in the solution of Polya's 2D drunkard problem.
%H A185280 P. Flajolet and R. Sedgewick, <a href="http://algo.inria.fr/flajolet/Publications/books.html">Analytic Combinatorics</a>, 2009; p. 425-426.
%F A185280 1 + Sum_{n>=1} binomial(2*n, n)^2/16^n - 1/(Pi*n).
%F A185280 Equals 1 + (4*log(2) - Pi)/Pi.
%F A185280 Equals 4*log(2)/Pi. - _Michel Marcus_, Jul 28 2016
%e A185280 0.882542400610606373585825728471990763930758994918621881957052934828487068186...
%t A185280 1+(4*Log[2]-Pi)/Pi // N[#, 100]& // RealDigits // First
%o A185280 (PARI) 4*log(2)/Pi \\ _Michel Marcus_, Jul 28 2016
%Y A185280 Cf. A016639, A163973.
%K A185280 nonn,cons,easy
%O A185280 0,1
%A A185280 _Jean-François Alcover_, Apr 23 2013
%E A185280 a(99) corrected by _Georg Fischer_, Jul 12 2021