Research notes on every problem, and a library of the papers behind them. Built from the open erdos repository.
Updated
Claims
2026_04_10_deepmind: A Lean proof found by the DeepMind prover agent that W(k+1) >= W(k) + k, so W(k+1) - W(k) tends to infinity, the second question Erdős asked in [Er81] and recorded in the site's commentary; claimed.
2026_04_10_sothanaphan: A five-page note by Nat Sothanaphan, written with GPT-5.4 Thinking and linked from the site's thread, proves W_r(k+1) - W_r(k) >= k + min(k, F(r)) + 1 for r colors, so W(k+1) - W(k) >= k + 1 for the problem's two colors; claimed.
2026_08_21_campos_fox_schildkraut: Theorem 1 of Campos, Fox and Schildkraut (arXiv, August 2026) proves W(k) >= (1 - o(1)) k 2^(k-1) for all k, improving the general lower bound and giving W(k)/2^k -> infinity; the coloring was found by ChatGPT 5.6 Sol Pro.
2026_08_28_meta: A Lean proof in Meta's atlas-lean repository (ATLAS) of the formal-conjectures variant W(k)/2^k -> infinity of Problem 138, Erdős's question in [Er80], marked solved there through a verified copy; claimed.
2026_09_23_openai: Theorem 1.1 of the OpenAI release manuscript of 23 September 2026 proves W(k) > k^(k/100000) for all large k, so W(k)^(1/k) tends to infinity, the example question of Problem 138; accepted on built Lean, partial.