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A divisor-function record beyond 24

Let τ(n) count the positive divisors of n. Is there some n > 24 such that max over m < n of (m + τ(m)) is at most n + 2?

Why this problem

The first genuine discovery target: a short statement with a compact deterministic witness and a natural optimized-search harness.

Verification contract

A positive answer is one explicit integer plus a bounded exact divisor-count check.

Tracking
Difficulty
4/10
Attempts
2
Last attempt
2026-07-20 16:26 UTC
Source status
verifiable
External validation
none
Techniques and harnesses
divisor sieverecord sequence searchbranch and boundOEIS cross-check
Resumable campaign memory

Research map

2 epochs · 0 promising · 2 blocked · 0 ruled out
Next session checkpoint

Independently review or run the reported frontier certificate through approximately 6.16e17.

First action: Independently review or run the reported frontier certificate through approximately 6.16e17.

Stop or redirect when: The planned discriminator resolves the route.

Open leads
  • No open lead is checkpointed.
Strategy registry
  • unspecified
    Exact divisor-incidence sieve with the recurrence R(n+1)=max(R(n), n+tau(n)), independently audited by trial-division factorization and direct maximization.
  • unspecified
    Headless research pass
Ruled out, with scope
  • Nothing has been rigorously ruled out yet.
Complete history

Attempts on this problem

2026-07-20 16:26 UTCOpen-problem program · 3 min

A divisor-function record beyond 24

Exact divisor-incidence sieve with the recurrence R(n+1)=max(R(n), n+tau(n)), independently audited by trial-division factorization and direct maximization.

What this run accomplished

No candidate was found. The C search exactly checked every n in [25, 10^7], with minimum R(n)-n equal to 3 at n=35. A separate Python trial-division audit agreed through 200,000 and recovered the known terms 5, 8, 10, 12, 24. This does not improve the stronger reported human computational bounds.

Next: Independently review or run the reported frontier certificate through approximately 6.16e17.

2026-07-20 16:21 UTCOpen-problem program · 0 min

A divisor-function record beyond 24

Headless research pass

What this run accomplished

The pass did not produce a valid research result: RuntimeError: Codex failed rc=1: WARNING: proceeding, even though we could not create PATH aliases: Read-only file system (os error 30) Error: failed to initialize in-process app-server client: Read-only file system (os error 30)

Next: Repair the failed pass and rerun.