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 A090852 #12 Sep 28 2019 04:27:29
%S A090852 1,4,7,10,13,16,20,24,27,31,35,39,43,47,51,55,60,64,68,73,77,81,86,90,
%T A090852 95,100,104,109,113,118,123,127,132,137,142,146,151,156,161,166,171,
%U A090852 176,181,186,191,196,201,206,211,216,221,226,231,236,241,246,251,256,262
%N A090852 a(n) is the least positive integer such that the integer part of the arithmetic-geometric mean of a(n) and 1 is equal to n.
%H A090852 Vaclav Kotesovec, <a href="/A090852/b090852.txt">Table of n, a(n) for n = 1..10000</a>
%F A090852 floor( agm(a(n), 1) ) = n, for n>=1.
%t A090852 Table[Ceiling[y /. FindRoot[Pi/(2*EllipticK[1 - y^2]) == n, {y, 2*n}]], {n, 1, 60}] (* _Vaclav Kotesovec_, Sep 28 2019 *)
%Y A090852 Cf. A090853, A090854.
%K A090852 nonn
%O A090852 1,2
%A A090852 _Paul D. Hanna_, Dec 10 2003