We have

a₂ – a₁ = – = , a₃ – a₂ = – = , a₄ – a₃ = – =

As (a_k+1 – a_k) is the same for k = 1, 2, 3, etc., the given list of numbers is an AP

Now, for this AP we have a = and d =

We choose to begin with the assumption that 301 is nth term of the this AP. We will see if an ‘n’ exists for which a_n = 301

We know

a_n = a + (n – 1) d

So, for 301 to be a term we must have

= + (n – 1) ×

or = n –

But n should be a positive integer.

So, 301 is not a term of the given list of numbers.