Solutions to Five Challenge Problems in Enumerative and Algorithmic Combinatorics, with an Account of the Human-Machine Methodology Employed

Jaideep Sai Padhi

For the two-layer solid standard Young-tableau shape [[n,n],[n,1]], Padhi gives an explicit two-term hypergeometric formula for the count g(n) and proves the conjectured second-order degree-12 recurrence for every n≥1.

Sources for this record

What was already known

Zeilberger computed the counts through n=40 and guessed the recurrence. Those finite values did not prove it for all n.

AI involvement AI-led

Padhi selected the challenge, directed the work, ran independent checks and rejected faulty proposals. He credits Claude with the mathematical ideas, proof and verification code.

Claude generated the proof and mathematical ideas under Padhi’s selection and falsification protocol.

Importance Notable

Resolves a specific enumerative-combinatorics challenge with a formula and all-n proof.

Limitations

Two independent dynamic programs agreed on 56 terms, and the derived recurrence matched those terms. Those finite checks do not verify the complete symbolic proof; no complete independent check is documented.

Technical verification Partial

Two independent dynamic programs agree on 56 finite terms and the derived operator annihilates them. That exact finite test checks cases, not the complete symbolic all-n argument; no complete human or machine check is documented.

Human understanding Few

Padhi explains the testing protocol, but the source credits Claude with the proof and does not document his independent explanation of its reverse-Kreweras derivation; Few is the evidence default.

Correction and publication history

2026-10-18 · publication

Resolves a specific enumerative-combinatorics challenge with a formula and all-n proof.

Read this published revision