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The 21 pages that link to Modular form, each with the reason it gives.
Elliptic functionRelated: Lattice invariants of elliptic functions lead naturally to modular forms.
q-seriesRelated: Many q-series become modular forms, bringing powerful tools to their coefficients.
Gotthold EisensteinRelated: Eisenstein series became foundational examples in this theory.
Ono's inequalityNarrower topic: Modular forms underlie many modern results about partition numbers.