133432831domain: NAppears in sequencesPerfect powers n such that (n-5)/2 is prime.at n=19A075539a(n) = (n^3 - 1)^3.at n=7A117197Number 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=8A128831a(n) = Product_{i=0..2} (2^floor((n+i)/3)-1).at n=27A274626