Ignoring the exponential terms, the closest I arrived is this:
Table[(-m)^(n - 1)/(n + 1)!
(n + n^2 + (m - a[n]) m),
{n, -1, 4}]
where a[n] should come from
FindSequenceFunction[{0, 2, 4, 6, 4, 5}, n]
if only it gave an answer. I was disappointed that this too gave no answer:
FindSequenceFunction[{2, 6, 24, 120}, n]