Robert A. Heinlein vs Heinlein

Robert A. Heinlein and Heinlein both are nouns.

Word	Noun	Adjective	Verb	Adverb
Robert A. Heinlein	Yes	No	No	No
Heinlein	Yes	No	No	No

As nouns, Robert A. Heinlein and Heinlein are synonyms defined as:

Robert A. Heinlein and Heinlein: United States writer of science fiction (1907-1988)

Other synonyms of Robert A. Heinlein include Robert Anson Heinlein.

Robert A. Heinlein (noun)	Heinlein (noun)
United States writer of science fiction (1907-1988)	United States writer of science fiction (1907-1988)