1127352domain: NAppears in sequencesa(0)=1, a(n) = a(n-1) - Sum_{k=2..n} mu(k) * a(n-k), where mu(k) is the Moebius function of k.at n=23A072810Number of length n+2 0..5 arrays with no three unequal elements in a row and new values 0..5 introduced in 0..5 order.at n=13A243636