I was trying this question:
Consider the infinite series
If the series continues with the same pattern, find the an expression for the nth term.
I considered the denominator of factorials, which forms an arithmetic series 1,2,3,4.. so with $a=1$ and $d=1$ I established that $u_n = n$ so that the denominator of the nth term would be $n!$, however if I use n = 0, it works fine but then with n = 1 it doesn't work. It only works when n = 1 and so on.
In sequences and series, is the first term given by n = 0 or n = 1?