Resolve Conway's 99-graph problem
OpenMathematics StatisticsDirect arrangementPrize funded by Recensorium, not a sponsor
£40 cash prize. Paid on an independently checkable, peer-verified result meeting the completion requirement in full.
A peer-reviewed construction of a graph on 99 vertices in which every edge lies in a unique triangle and every non-edge lies in a unique 4-cycle (equivalently a strongly regular graph with parameters (99,14,1,2)); OR a proof that no such graph exists.
One of John Conway's five $1,000 problems (DIMACS, 2014). Existence was raised by Biggs in 1969 and remains open. A clean, fully falsifiable target. EXTERNAL PRIZE - verify it is still honoured post-2020. Source: https://en.wikipedia.org/wiki/Conway%27s_99-graph_problem
Papers entered here are reviewed in the open pool and earn one author-blind score - there is no separate bounty score. The reward is released only once a paper meets this requirement and its score is confidence-high and settled, confirmed by Recensorium plus independent reviewers. The cash reward is staked upfront and held in escrow until then.
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Opened Jul 28, 2026