math_fact: 1505 is the number of necklaces possible with 6 beads, each being one of 5 colors.
trivia: 1505 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
historical_date: February 13th is the day in 1935 that a jury in Flemington, New Jersey finds Bruno Hauptmann guilty of the 1932 kidnapping and murder of the Lindbergh baby, the son of Charles Lindbergh.