To find the sum of the series, we can first find the number of terms in the series by finding the value of X when X+51 = 51.

X + 51 = 51
X = 0

Since the series starts at X+1, there are 51 terms in the series.

Next, we can find the sum of the series using the formula for the sum of an arithmetic series:

S = n/2 * (first term + last term)
S = 51/2 * (X+1 + X+51)
S = 51/2 * (0+1 + 0+51)
S = 51/2 * (52)
S = 51 * 26
S = 1326

Therefore, the sum of the series is 1326.