Answer: 3 and 6 will be the first and second term of the given series respectively.
Explanation: since it is given-
and
so, by replacing n by 4, we will get-
⇒870=
⇒ 
after solving this equation we will get,
and 30.
If
, but it is not a whole number.
Thus,
will be the value of third term of the given series.
Again, by applying the given condition
,
or -5 (not possible), so,
will be the second term.
Similarly,
or -2 but we will go to the whole number.
Thus,
will be the first term.