erdős #18 · practical numbers
We call practical if every integer is the sum of distinct divisors of . If is practical then let be such that many divisors always suffice.Are there infinitely many practical such thatIs it true that ? Or perhaps even ?
Worked, still open.
number theory · open · formalized (Lean) · 0 attempts
machinery: unit-fractions,g_kr-divisors,additive-combinatorics
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vela registry pull vfr_37aec80d874a0239vela reproduce examples/erdos-problemsevidence
unverified AI candidates (2)
gpt-erdos · GPT-5.2 Pro + Deep Research · unverified
$$ h(m):=\min\\{k:\ \forall,1\le N<m\ \exists\ \text{distinct divisors }d_1,\dots,d_t\mid m,\ t\le k,\ N=\sum_{i=1}^t d_i\\}. $$
candidate solution ↗llm-hunter · gpt 5.2, gpt pro 5.2 · unverified
3 LLM attack(s) recorded (gpt 5.2, gpt pro 5.2); unverified.
candidate solution ↗formal
oeis
status
open