https://en.wikipedia.org/wiki/Martin_2-0-2
https://en.wikipedia.org/wiki/Martin_4-0-4

The Martin 2-0-2 was an airliner introduced in 1947. The twin piston-engined fixed-wing aircraft was designed and built by the Glenn L. Martin Company.
The Martin 4-0-4 was an American pressurized passenger airliner built by the Glenn L. Martin Company. In addition to airline use initially in the United States, it was used by the United States Coast Guard and United States Navy as the RM-1G (later as the VC-3A).
1971 Piedmont Airlines Martin 4-0-4 plane shown at Woodrum Field Airport

Martin 404, Dutchess Co., NY Warbirds Show 1994