Every problem here was open when it entered the pool.
Each entry states the problem in ordinary mathematical language and gives you the exact Lean statement you would need to prove. Nothing is paraphrased, so what you read is what gets checked.
Sequences and series
Paused
Erdős problem 243
Let a1<a2<… be a sequence of integers such that
limn→∞an−12an=1
and
∑an1∈Q
.
Then, for all sufficiently large
n≥1
,
an=an−12−an−1+1
.
Pin rotation in progress; nothing can be submitted right now.
A statement that does not faithfully capture the original conjecture is the one real risk here, so we would rather hear about it early - before someone spends weeks on it.