We need to find the sum of the series {2² + 4² + 6² + …. + (2n)²}.

So, we can find it by using summation of the n^th term of the given series.

The n^th term of the series is (2n) ² = 4n²

(Given data)

a_n = 4n²

Now, sum of the series,

Note:

I. Sum of squares of first n natural numbers, 1² + 2² + 3²+….n²,