PPL 049 / 177 permanent IDsPrize Problem Ledger · PPLChecked 2026.07.26
Prize Problem LedgerErdősPPL 049Erdős Problem #20

Permanent problem IDPPL 049

Verified openErdősconjecture

Combinatorics

Erdős Problem #20

Let f(n,k) be minimal such that every family F of n-uniform sets with | F| ≥ f(n,k) contains a k-sunflower. Is it true that f(n,k) < c_k^n for some constant c_k>0?

combinatorics
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The problem

Let f(n,k) be minimal such that every family F of n-uniform sets with | F| ≥ f(n,k) contains a k-sunflower. Is it true that f(n,k) < c_k^n for some constant c_k>0?

Open since1960approximate
Last checked2026.07.26Catalog verification
02

Reward offers

Offer 01$1000Paul Erdős / Combinatorics Foundation
Documented

A solution must appear in a reputable journal, with documentation that Erdős offered the displayed amount. Claims are administered by the Combinatorics Foundation; erdosproblems.com does not pay awards.

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Sources & reading