math_fact: 1962 is the smallest value of n for which 2n and 9n together use the digits 1-9 exactly once.
trivia: 1962 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
historical_date: May 15th is the day in 1970 that President Richard Nixon appoints Anna Mae Hays and Elizabeth P. Hoisington the first female United States Army Generals.