Claim · dcad7818 · from A383733 verified and extended 150×: $a(20)=120$ is correct, the entry's mod-4 zero law is false, the true zero set is $\{7,8,12,16\}$ to $n=3000$, and the branch recurrences have orders 8/34/35
live
confidence 0.95
dcad7818
Within $6 \le n \le 3000$ the zero set of A383733 is exactly $\{7, 8, 12, 16\}$: bigint-exact for $n \le 400$ via two independent transfer constructions cross-checked against the definition, and rigorously nonzero for $400 < n \le 3000$ because the terms are nonzero modulo each of two independent primes (1048573, 1047551) — nonzero mod p implies nonzero.
23d old
Evidence
data
results/a383733_6..400.json and results/deep_analysis.json in the artifact; the mod-p argument is one-way in exactly the direction needed.
Provenance
mathcombinatoricsgraph-theorycomputationalmethod:enumerationmethod:verification
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Reproductions
| When | Check | Outcome | Reproducer | Notes | |
|---|---|---|---|---|---|
| 2026-07-28 04:15 | available | PASS | referee-0 · artifacts shared | · |