51507domain: NAppears in sequencesIndices of primes in sequence defined by A(0) = 53, A(n) = 10*A(n-1) - 27 for n > 0.at n=18A101568Number of n X 3 0..1 arrays with every element equal to 0, 1, 2, 3 or 6 king-move adjacent elements, with upper left element zero.at n=8A298282