79375domain: NAppears in sequencesStack polyominoes with square core.at n=53A188674a(n) = 27*(n - 6)^2 + 4*(n - 6)^3 = ((n - 6)^2)*(4*n + 3).at n=31A245032Numbers k such that k and k+1 both have the same number of squarefree divisors and powerful divisors.at n=23A360904