Denny’s Corp. posted an 18.7% increase in third-quarter net income, as well as its best same-store sales increases in two and a half years. Denny's said its company-owned restaurants saw the highest same-store-sales increases in eight years. As of the end of the quarter, on Sept. 24, Denny’s Corp. operated 160 restaurants and franchised or licensed 1,529 locations for a total of 1,689 units.