72630domain: NAppears in sequencesa(n) = (7*n + 3)*(7*n + 4).at n=38A177071a(n) = 81*n^2 - 9*n.at n=30A277991Number of length n inversion sequences avoiding the patterns 120, 201, and 210.at n=9A279572a(n) = Sum_{k=1..n} phi(k)*phi(k+1)*phi(k+2), where phi(k) = A000010(k) is Euler's totient function.at n=33A335131