Chess 960 posible starting positions

Examples in several programming languages
http://rosettacode.org/wiki/Generate_Chess960_starting_position

All the positions with the standard ID number
https://chess960.net/wp-content/uploads/2018/02/chess960-starting-positions.pdf

https://www.chessprogramming.org/Chess960

https://github.com/MichaelB7/Chess960-Lookup/blob/master/src/960v09.c

https://en.wikipedia.org/wiki/Fischer_Random_Chess_starting_position

Very good explanation of the rules
https://codegolf.stackexchange.com/questions/12322/chess960-position-lookup/12333#12333

B   B   Q   N   N   R K R
4 * 4 * 6 * 5 * 4 * 1     = 1920

Bishops have to be of different colors (4 black squares, 4 whites squares).

There is only 1 possible position for the King and Rooks because it has to go
between the Rooks and there are only 3 squares available at that time.

Because the Knights change color when they move they could be interchanged
without any difference then 5 * 4 should be divided by 2 then
total number of positions = 960.