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Decimal expansion of circumference of 4 x^2 + 9 y^2 = 36.
1

%I #4 Jun 15 2020 13:39:43

%S 1,5,8,6,5,4,3,9,5,8,9,2,9,0,5,8,9,7,9,1,3,3,1,6,6,3,0,2,7,7,8,3,0,7,

%T 2,4,9,6,7,3,0,0,8,2,8,4,8,3,2,6,5,0,0,6,8,9,6,6,7,2,6,3,1,1,7,7,4,2,

%U 4,8,2,2,3,9,1,0,9,6,8,8,9,9,5,9,1,4

%N Decimal expansion of circumference of 4 x^2 + 9 y^2 = 36.

%F arclength = 8 E(-5/4), where E = complete elliptic integral.

%e arclength = 15.8654395892905897913316630277830724967300828483...

%t s = Integrate[Sqrt[D[ 3 Cos[t], t]^2 + D[2 Sin[t], t]^2], {t, 0, 2 Pi}]

%t r = N[s, 200]

%t RealDigits[r][[1]]

%Y Cf. A333202, A334848.

%K nonn,cons,easy

%O 1,2

%A _Clark Kimberling_, Jun 15 2020