How many children did Rob and Laura Petrie have on "The Dick Van Dyke Show"?

"The Dick Van Dyke Show" is an American television sitcom that initially aired on CBS from October 3, 1961 to June 1, 1966, with a total of 158 half-hour episodes spanning over five seasons. The show was created by Carl Reiner and starred Dick Van Dyke, Rose Marie, Morey Amsterdam, Larry Mathews, and Mary Tyler Moore. It centered on the work and home life of television comedy writer Rob Petrie (Van Dyke).

Many scenes deal with Rob and his co-writers, Buddy Sorrell (Morey Amsterdam) and Sally Rogers (Rose Marie). Mel Cooley (Richard Deacon), a balding straight man and recipient of numerous insulting one-liners from Buddy, was the show's producer and the brother-in-law of the show's star, Alan Brady (Carl Reiner). As Rob, Buddy, and Sally write for a comedy show, the premise provides a built-in forum for them to constantly make jokes. Other scenes focus on the home life of Rob, his wife Laura (Mary Tyler Moore), and only child, son Richie (Larry Mathews), who live at 148 Bonnie Meadow Road in suburban New Rochelle, New York. Also often seen are their next-door neighbors and best friends, Jerry Helper (Jerry Paris), a dentist, and his wife Millie (Ann Morgan Guilbert).

Rob and Laura's son's middle name is an acronym for "Robert Oscar Sam Edward Benjamin Ulysses David," all the names suggested by members of Rob and Laura's families in the episode "What's in a Middle Name?".