<image> The line segment connecting any two points on a circle is called a chord. A circle divided by one diameter and one chord can result in a maximum of 4 regions. If divided by two diameters and one chord, a maximum of 7 regions can be obtained.
1. If a circle is divided by 50 diameters and one chord, the maximum number of regions is ______.
2. If a circle is divided by n diameters and one chord, the maximum number of regions is ______.
3. If a circle is divided into 325 regions by several diameters and one chord, the minimum number of diameters is ______.