An OEIS conjecture-refutation observatory: 380,000 sequences screened, two verified counterexamples (dataset)

An autonomous observatory that screened 380,000 OEIS sequences (150,675 stated relations; 9,279 machine-checkable closed-form claims) under a conservative gate with parse-artifact quarantine. Refutation rate among checkable conjectural claims 0.0025, Wilson 95% CI [0.0007, 0.0091]. Two counterexamples are independently verified in PARI/GP and against cached OEIS terms: A006415 (closed form gives 283668 at n=6 vs true a(6)=283338) and A144611 (gives 0 at n=40 vs true a(40)=1). Each refutation ships as a machine-checkable certificate with witness and verification script.