Ramanujan's sum

noun

A function, usually denoted c_q(n), of two positive integer variables q and n, defined by the formula c_q(n)=∑_(1<a≤q atop (a,q)=1)e^(2πi tfrac aqn),, where (a, q) = 1 means that a only takes on values coprime to q. It is used in the proof of Vinogradov's theorem.

Meanings

nounRamanujan's sum (plural Ramanujan's sums)

plural Ramanujan's sums

  1. mathematicsA function, usually denoted c_q(n), of two positive integer variables q and n, defined by the formula c_q(n)=∑_(1<a≤q atop (a,q)=1)e^(2πi tfrac aqn),, where (a, q) = 1 means that a only takes on values coprime to q. It is used in the proof of Vinogradov's theorem.
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APA

Ramanujan's sum. (n.d.). In WatkinsX Dictionary. Retrieved November 5, 2026, from https://dictionary.watkinsx.com/word/Ramanujan's%20sum

MLA

“Ramanujan's sum.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/Ramanujan's%20sum. Accessed November 5, 2026.

Chicago

WatkinsX Dictionary, s.v. “Ramanujan's sum,” accessed November 5, 2026, https://dictionary.watkinsx.com/word/Ramanujan's%20sum.

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