A038021 Triangle: T(n,k), k<=n: commutative groupoids with n elements and k idempotents.
1, 0, 1, 1, 2, 1, 38, 57, 27, 7, 13872, 18544, 9280, 2080, 192, 83360520, 104208775, 52110500, 13035000, 1632750, 82355
Offset: 0
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