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 A191220 #15 Jul 22 2025 12:07:40 %S A191220 6,5,6,1,7,6,3,4,3,5,5,8,6,8,3,5,3,5,9,9,1,7,8,0,0,1,5,7,8,1,5,2,3,0, %T A191220 3,9,0,8,9,0,4,7,9,0,4,2,8,0,0,6,8,6,5,5,1,3,1,9,2,4,4,8,6,0,3,0,5,5, %U A191220 2,9,1,4,0,1,5,3,7,5,7,7,9,4,3,5,3,3,0,0,6,9,0,8,9,9,6,9,7,1,5,6,4,8,3,3,9,5,9,8,4,7 %N A191220 Decimal expansion of x, where Arithmetic-Geometric Mean of 1 and x = Pi. %t A191220 SetPrecision[ %t A191220 Nest[((x - (ArithmeticGeometricMean[1, x] - Pi)/ %t A191220 D[ArithmeticGeometricMean[1, x] - Pi, x]) /. x -> #1) &, 6, %t A191220 5], 50] %o A191220 (PARI) \p 120 %o A191220 solve(x=5,10,agm(x,1)-Pi) %K A191220 nonn,cons %O A191220 1,1 %A A191220 _Joshua Taylor_, May 26 2011