Assuming you mean
first term is n=1, so 1²+3=1+3=4
2nd is n=2 so 2²+3=4+3=7
3rd is n=3 so 3²+3=9+3=12
the first 3 terms are 4,7,12
first term is n=1, so 1²+3=1+3=4
2nd is n=2 so 2²+3=4+3=7
3rd is n=3 so 3²+3=9+3=12
the first 3 terms are 4,7,12
