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A129658 Numerators of the convergents of the continued fraction for L(3, chi3), where L(s, chi3) is the Dirichlet L-function for the non-principal character modulo 3. 15

%I #7 Dec 10 2016 03:03:09

%S 0,1,0,1,7,8,15,23,38,61,343,404,747,7127,29255,387442,1579023,

%T 1966465,5511953,150789196,156301149,4527221368,4683522517,

%U 13894266402,32472055321,111310432365,255092920051,1896960872722,2152053792773

%N Numerators of the convergents of the continued fraction for L(3, chi3), where L(s, chi3) is the Dirichlet L-function for the non-principal character modulo 3.

%D Leonhard Euler, "Introductio in Analysin Infinitorum", First Part, Articles 176 and 292

%F chi3(k) = Kronecker(-3, k); chi3(k) is 0, 1, -1 when k reduced modulo 3 is 0, 1, 2, respectively; chi3 is A049347 shifted.

%F Series: L(3, chi3) = Sum_{k>=1} chi3(k) k^{-3} = 1 - 1/2^3 + 1/4^3 - 1/5^3 + 1/7^3 - 1/8^3 + 1/10^3 - 1/11^3 + ...

%F Closed form: L(3, chi3) = 4 Pi^3/(81 sqrt(3)).

%e L(3, chi3) = 0.8840238117500798567430579168710118077... = [0; 1, 7, 1, 1, 1, 1, 1, 5, 1, 1, 9, 4, 13, 4, ...], the convergents of which are 0/1, 1/0, [0/1], 1/1, 7/8, 8/9, 15/17, 23/26, 38/43, 61/69, 343/388, 404/457, 747/845, 7127/8062, 29255/33093, 387442/438271, 1579023/1786177, ..., with brackets marking index 0. Those prior to index 0 are for initializing the recurrence.

%t nmax = 100; cfrac = ContinuedFraction[4 Pi^3/(81 Sqrt[3]), nmax + 1]; Join[ {0, 1}, Numerator[ Table[ FromContinuedFraction[ Take[cfrac, j] ], {j, 1, nmax + 1} ] ] ]

%Y Cf. A129404, A129405, A129406, A129407, A129408, A129409, A129410, A129411.

%Y Cf. A129659, A129660, A129661, A129662, A129663, A129664, A129665.

%K nonn,frac,easy

%O -2,5

%A _Stuart Clary_, Apr 30 2007

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