144228domain: NAppears in sequencesG.f.: Sum_{n>=0} x^n * Product_{k=1..n} (k - 2*x) / (1 - 2*k*x).at n=7A231173Number of nX4 0..2 arrays with no element equal to any value at offset (-2,-1) (-2,0) or (-1,-1) and new values introduced in order 0..2.at n=9A275500