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Because all summands are machine integers Mathematica can use internal.
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Publishing, pp. 423–446, MR 0827799, Zbl 0634. Let us compare the timings of various ways to sum the term of longList.
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Japan 1984 (Tokyo, Okayama and Kyoto, 1984), Singapore: World Sci. (1985), "On congruences arising from relative Gauss sums", Number theory and combinatorics.
#Summation in mathematica how to
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system like GiNaC 38, FORM 39 or the commercial ones like Mathematica or Maple. Keywords: Lattice sum Helmholtz equation Ewald summation lattice reduction Clausen function Schlmilch series. (1979), "Sums of Gauss, Eisenstein, Jacobi, Jacobsthal, and Brewer", Illinois Journal of Mathematics, 23 (3): 374–437, ISSN 0019-2082, MR 0537798, Zbl 0393.12029 algebraic structure of nested sums forms a Hopf algebra 36, 37.
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