Fatto matematico: 6861 is a value of n for which s(n-1) + s(n+1) = s(2n).
Trivia: 6861 is an unremarkable number.
Data storica: October 13th is the day in 1845 that a majority of voters in the Republic of Texas approve a proposed constitution, that if accepted by the U.S. Congress, will make Texas a U.S. state.