298378080domain: NAppears in sequencesNumber of (n+2) X 8 binary arrays avoiding patterns 001 and 101 in rows and columns.at n=18A202200a(n) is the smallest number k that is divisible by all numbers d with d < p = prime(n), and such that all of k+1, k-1, k+p, k-p are prime.at n=4A354882