{"schema":"vela.problem-packet.v0.1","problem":858,"statement":"Let $A\\subseteq \\{1,\\ldots,N\\}$ be such that there is no solution to $at=b$ with $a,b\\in A$ and the smallest prime factor of $t$ is $>a$. Estimate the maximum of\\[\\frac{1}{\\log N}\\sum_{n\\in A}\\frac{1}{n}.\\]","status":"solved","seam":"raw","closureRoutes":[],"obligations":[],"attestations":[],"attempts":[],"velaLean":[],"oeis":[],"generated_note":"derived view; the signed event log is the source of truth (vela check / vela reproduce)"}