Solutions, solvers and records for "Improved upper bounds for seventeen IHTC-2024 benchmark instances from solvers written by an AI coding agent"

Solution files and records for the note "Improved upper bounds for seventeen IHTC-2024 benchmark instances from solvers written by an AI coding agent". The 17 solutions improve the best-known upper bounds listed on https://ihtc2024.github.io/ihtp/ as of 29 October 2026 for public instances i02, i07, i08, i09, i10, i12, i14, i15, i17, i19, i21, i22, i23, i25, i26, i29 and i30. Each has zero hard-constraint violations under the official IHTP validator. The solvers that produced them were written by Claude Opus 5.5 in Claude Code, one per public instance, each in a one-hour session without internet access and without human-written code. ihtp-llm-ub-note-solutions.zip contains the 17 solution files in the competition's JSON format, their SHA-256 digests, the official validator's output and that of an independent evaluator for each file, and the code review of each solver version that produced a solution. ihtp-llm-ub-note.zip contains the full record: all 212 committed solver versions, the 30 development-session transcripts and proxy logs, all 2,120 evaluation runs (600 s, 4 threads, 10 seeds per version), the scripts that regenerate every number of the note, and the baselines. To verify a solution, compile the official validator from https://ihtc2024.github.io/ and run it on the solution with the corresponding instance file.