997815domain: NAppears in sequencesNumber of 3 X n 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 0 1 and 1 0 1 vertically.at n=10A207600Least k with precisely n partitions k = x + y satisfying x > 0 and k' = x' + y', where k', x', y' are the arithmetic derivatives of k, x, y.at n=20A212664