The following information:
"nth term of a sequence is n2+1"
gives you the general formula for the terms in the sequence. In order to find out a specific term, you need to substitute it's ordinal number for the n:
so, instead of n2+1
we have 9 2+1
now, did you mean here:
n*2+1?
then you have 9*2+1=19
but I think you meant a power, like this:
n²+1, correct?
then we have:
9[tex]^{2} [/tex]+1=81+1=82