[Atlas Shrugged] book attracted a coterie of fans, some of them top corporate executives, who dared not speak of its impact except in private. “I know from talking to a lot of Fortune 500 C.E.O.’s that ‘Atlas Shrugged’ has had a significant effect on their business decisions, even if they don’t agree with all of Ayn Rand’s ideas,” said John A. Allison, the chief executive of BB&T, one of the largest banks in the United States. One of Rand’s most famous devotees is Alan Greenspan, the former chairman of the Federal Reserve, … Mr. Greenspan met Rand when he was 25 and working as an economic forecaster. She was already renowned as the author of “The Fountainhead,” a novel about an architect true to his principles. Mr. Greenspan had married a member of Rand’s inner circle, known as the Collective, that met every Saturday night in her New York apartment.