Question 1006335
.
n = 1: {{{a[1]}}} = 3;


n = 2: {{{a[2]}}} = 8;


n = 3: {{{a[3]}}} = 13;


n = 4: {{{a[4]}}} = 18;


n = 5: {{{a[5]}}} = 23.


Arithmetic progression. The first term 3. The common difference is 5.