205 (number) explained

Number:	205
Divisor:	1, 5, 41, 205

205 (two hundred [and] five) is the natural number following 204 and preceding 206.

In mathematics

205 is a lucky number,^[1] and a Wolstenholme number.^[2] On an infinite chessboard, a knight can reach exactly 205 squares within four moves.^[3] There are 205 different ways of forming a connected graph by adding six edges to a set of five labeled vertices.^[4]

In other fields

• The atomic number of an element temporarily called Binilpentium

See also

• List of highways numbered 205
• 205 Martha, a large Main belt asteroid
• 205 Yonge Street, a building in Toronto
• 205 series, a commuter train type in Japan
• Peugeot 205, a French car
• WWE 205 Live, an American professional wrestling program

Notes and References

1. Lucky numbers.
2. Wolstenholme numbers.
3. Number of squares on infinite chess-board at <= n knight's moves from a fixed square.
4. Number of connected labeled graphs with n nodes and n+1 edges.