Offer 01$1,000 proof · $200 counterexampleZhi-Wei Sun
Personal offerUS$1,000 is offered for the first positive resolution of both parts; US$200 is offered for the first explicit counterexample to either part.
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The problem
Prove both that every natural number except 216 is a prime-or-zero plus a triangular number, and that every odd integer greater than 3 is a prime plus x(x+1) for some positive integer x—or give an explicit counterexample to either part.
Open since2008paper formulation
Last checked2026.07.27Catalog verification
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Reward offers
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