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Decimal expansion of Sum_{n>=1} ((-1)^(n-1))*arctan(n)/n.
2

%I #15 Apr 21 2021 12:00:16

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

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

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

%N Decimal expansion of Sum_{n>=1} ((-1)^(n-1))*arctan(n)/n.

%C The alternating series test shows the series is convergent.

%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Alternating_series_test">Alternating series test</a>.

%F Equals Sum_{n>=1} ((-1)^(n-1))*arctan(n)/n.

%e 0.46571230352630363552682770124023013687237216061516248...

%p evalf(sum(((-1)^(n-1))*arctan(n)/n, n=1..infinity),120);

%o (PARI) sumalt(n=1, (-1)^(n-1)*atan(n)/n) \\ _Michel Marcus_, Apr 17 2021

%Y Cf. A343469, A265011.

%K nonn,cons

%O 0,1

%A _Bernard Schott_, Apr 17 2021