An intercalate is a 2 X 2 subsquare of a Latin square.
Table of n, a(n) for n=1..8.
E. I. Vatutin, Discussion about properties of diagonal Latin squares at forum.boinc.ru (in Russian)
Index entries for sequences related to Latin squares and rectangles
Cf. A307163, A092237.
Sequence in context: A139358 A004477 A328285 * A181829 A199693 A166206
Adjacent sequences: A307161 A307162 A307163 * A307165 A307166 A307167
Eduard I. Vatutin, Mar 27 2019