Erdős problem 1026
For a sequence of distinct reals, determine the largest constant such that some monotonic subsequence always has sum exceeding times the total sum. Resolved as .
Sources
FormalConjectures/ErdosProblems/
1026.lean
Retained formal statement
Hanani [Ha57] showed that every sequence is the disjoint union of at most many monotonic subsequences, whence .
1 / √2 ∈ Erdos1026.admissibleConstantsSolvedStatement only, no proof