Self-inductance is given by

Self-inductance per unit length is given by

Where is the permeability of the free space

n is the number of turns per unit length

A is Area of a cross section of the solenoid

L is the self-inductance

l is the length the wire

Therefore, self-inductance at the centre and that near its ends will be the same since the self -induction is independent of the distance of the point from the centre of the solenoid.