What is the 250th term of this sequence. explain. 4, 9,14,19,24

A1 = first term = 4
a2 = second term = a1+5 = 4+5 = 0
a3 = third term         a1 + 5 + 5 = a1 + 5(n-1), where n is the subscript that represents which term we're discussing.

an=4+5(n-1).

Is this correct?  Let's check it and find out.
What is your prediction for a2?  Here, n = 2.  Then a2 = 4+5(2-1), or 4+5, or 9.  That agrees with the given sequence rule.

Thus, the 250th term would be 4+5(250-1).  Evaluate this, please.