If In=∫01xne−xdxI_n = \int_0^1 x^n e^{-x} dxIn=∫01xne−xdx, which recurrence relation is correct?
In=nIn−1−1/eI_n = n I_{n-1} - 1/eIn=nIn−1−1/e
In=nIn−1+1/eI_n = n I_{n-1} + 1/eIn=nIn−1+1/e
In=(n−1)In−1−1/eI_n = (n-1) I_{n-1} - 1/eIn=(n−1)In−1−1/e
In=−nIn−1+1/eI_n = -n I_{n-1} + 1/eIn=−nIn−1+1/e