Anchored Stratification Arrays: designs and verification code

The anchored stratification arrays constructed in the paper "Anchored stratification arrays" by R. C. Karunanayaka, together with self-contained Python programs that reconstruct them from the descriptions given in the paper and check every claim made there in exact integer arithmetic. Included are arrays attaining the bound of n/2 - 1 factors in n runs at 16, 64, 256, 1024, and 4096 runs; the closed-form construction that attains the bound at every power of four, as the normalized Walsh transform of a quadratic form over a binary field (Theorem 5), with the program that evaluates it for any odd field degree; an ASA(32,11) and an ASA(32,10), which carry two and one factors more than any orthogonal array with 32 runs, together with the constraint-programming searches that found them and the exact linear programming bound that excludes an orthogonal array with ten four-level factors in 32 runs; an ASA(16,7) whose labels are linear but whose near sets are not affine subspaces; the exhaustive and orbit-restricted signing searches at GF(32), GF(128), and GF(512); the extension checks at 32 and 128 runs; and a verification program covering the defining conditions, the orthogonality characterization, the moment identities, the equality structure, the determinant identity behind the non-existence theorem, the weighing matrix and its design support, the closed-form construction, and the uniqueness of the 16-run array. Version 4 adds the closed-form construction, the 4096-run array, the two 32-run arrays, and the searches and bounds behind them.