The linear k-within-(r, s)-out-of-(m, n):F lattice system consists of mn components arranged in m rows and n columns and fails whenever there is at least one rectangle of dimension r × s which contains k or more failed components. We propose recursive formulas for the calculation of the linear k-within-(r, s)-out-of-(m, n):F lattice system. The computing complexity of the system reliability using the recursive formulas is O((n − s)ms+1 + m2s) for r = m and O((r + 1)rs(m−r+1)[(n − s)m + 2r(s−1)ms]) for r < m.