68669157375domain: NAppears in sequencesa(n) = (n^3 - 1)^3.at n=15A117197Number of n-tuples where each entry is chosen from the subsets of {1,2,3} such that the intersection of all n entries is empty.at n=11A128831a(n) = Product_{i=0..2} (2^floor((n+i)/3)-1).at n=36A274626