The 10th term counted from the last term of the arithmetic progression 4, 9, 14, …, 254 is:

Counting backwards from the end turns the progression into one with first term 254 and common difference −5, so the 10th term from the end is $254-9\times 5=209$. (214 subtracts only 8 steps; 204 subtracts 10 steps instead of 9 — the last term itself is the 1st from the end, not the 0th; 49 is the 10th term from the beginning.) Counting forwards agrees: $254=4+(n-1)5$ gives $n=51$ terms, and the 42nd term is $4+41\times 5=209$.