Based on the comments on [OEIS-A002387](https://oeis.org/A002387): $a_{n}$ = 1, 2, 4, 11, 31, 83, 227, 616,... it is likely, that the sequence $a_{n}$ coincides with $\lfloor e^{n-\gamma} +0.5\rfloor$ , where $\gamma$ is the Euler-Mascheroni constant (remark made by Dean Hickerson). My Question: Is there a formal proof, that OEIS-A002387 is $\lfloor e^{n-\gamma} +0.5\rfloor$ ?