The constants defined by
(1)
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These constants can also be written as the sums
(2)
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and
(3)
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(E. Weisstein, Feb. 3, 2015), where is the th positive root of
(4)
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and is the sinc function.
diverges, with the first few subsequent constant numerically given by
(5)
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(6)
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(7)
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Rather surprisingly, the even-ordered du Bois Reymond constants (and, in particular, ; Le Lionnais 1983) can be computed analytically as polynomials in ,
(8)
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(9)
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(10)
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(OEIS A085466 and A085467) as found by Watson (1933). For positive integer , these have the explicit formula
(11)
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where denotes a complex residue and is a Kronecker delta (V. Adamchik).