

A153069


Numerators of the convergents of the continued fraction for Catalan's constant L(2, chi4), where L(s, chi4) is the Dirichlet Lfunction for the nonprincipal character modulo 4.


6



0, 1, 0, 1, 10, 11, 98, 109, 9690, 38869, 48559, 87428, 660555, 14619638, 15280193, 45180024, 150820265, 3966506914, 4117327179, 49257105883, 53374433062, 583001436503, 636375869565, 6310384262588, 19567528657329
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OFFSET

2,5


LINKS

Table of n, a(n) for n=2..22.


FORMULA

chi4(k) = Kronecker(4, k); chi4(k) is 0, 1, 0, 1 when k reduced modulo 4 is 0, 1, 2, 3, respectively; chi4 is A101455.
Series: L(2, chi4) = Sum_{k>=1} chi4(k) k^{2} = 1  1/3^2 + 1/5^2  1/7^2 + 1/9^2  1/11^2 + 1/13^2  1/15^2 + ...


EXAMPLE

L(2, chi4) = 0.91596559417721901505460351493238411... = [0; 1, 10, 1, 8, 1, 88, 4, 1, 1, 7, 22, 1, 2, 3, 26, ...], the convergents of which are 0/1, 1/0, [0/1], 1/1, 10/11, 11/12, 98/107, 109/119, 9690/10579, 38869/42435, 48559/53014, 87428/95449, 660555/721157, ..., with brackets marking index 0. Those prior to index 0 are for initializing the recurrence.


MATHEMATICA

nmax = 100; cfrac = ContinuedFraction[Catalan, nmax + 1]; Join[ {0, 1}, Numerator[ Table[ FromContinuedFraction[ Take[cfrac, j] ], {j, 1, nmax + 1} ] ] ]


CROSSREFS

Cf. A006752, A014538, A054543, A104338, A118323, A153070.
Sequence in context: A046851 A045953 A136830 * A178569 A303605 A266946
Adjacent sequences: A153066 A153067 A153068 * A153070 A153071 A153072


KEYWORD

nonn,frac,easy


AUTHOR

Stuart Clary, Dec 17 2008


STATUS

approved



