The odd natural numbers are \(1\), \(3\), \(5\), ….
We need to find the value of \(1 + 3 + 5 + … + (2n - 1)\).
First term, \(a = 1\).
Common difference, \(d = 3 - 1 = 2\).
Last term, \(l = 2n - 1\).
This series is an \(A.P\).
If the first term \(a\), and the last term \(l\) are given, then .
Now, substitute the given values in \(S_n\).
\(S_n = n^2\)
Therefore, \(S_n = n^2\).
Sum of first \(n\) odd natural numbers \(= n^2\).