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%I #12 Sep 28 2019 04:27:29
%S 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 95,100,104,109,113,118,123,127,132,137,142,146,151,156,161,166,171,
%U 176,181,186,191,196,201,206,211,216,221,226,231,236,241,246,251,256,262
%N 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 Vaclav Kotesovec, <a href="/A090852/b090852.txt">Table of n, a(n) for n = 1..10000</a>
%F floor( agm(a(n), 1) ) = n, for n>=1.
%t Table[Ceiling[y /. FindRoot[Pi/(2*EllipticK[1 - y^2]) == n, {y, 2*n}]], {n, 1, 60}] (* _Vaclav Kotesovec_, Sep 28 2019 *)
%Y Cf. A090853, A090854.
%K nonn
%O 1,2
%A _Paul D. Hanna_, Dec 10 2003