Question: Egbert B. Gebstadter is a fictional author who appears in the indexes of books written by an American professor who was born in what year?
Sentence (from "Egbert B. Gebstadter"): His name is derived from "GEB", the abbreviation for Hofstadter's first book "Gödel, Escher, Bach: An Eternal Golden Braid"; the letters appear in his last name, permuted in his first name, and permuted again in his initials.
Relevant evidence: No