math_fact: 5513 is the number of self-avoiding walks of length 10.
trivia: 5513 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
historical_date: February 3rd is the day in 1995 that Astronaut Eileen Collins becomes the first woman to pilot the Space Shuttle as mission STS-63 gets underway from Kennedy Space Center in Florida.