1. **Problem statement:** Find the value of the infinite series \(\sum_{k=1}^\infty \frac{1}{k!}\).
2. **Recall the exponential series:** The Maclaurin series expansion for \(e^x\) is given by
$$e^x = \sum_{k=0}^\infty \frac{x^k}{k!} = 1 + \frac{x}{1!} + \frac{x^2}{2!} + \frac{x^3}{3!} + \cdots$$
3. **Apply the formula for \(x=1\):**
$$e^1 = e = \sum_{k=0}^\infty \frac{1^k}{k!} = \sum_{k=0}^\infty \frac{1}{k!} = 1 + \sum_{k=1}^\infty \frac{1}{k!}$$
4. **Isolate the series:**
$$\sum_{k=1}^\infty \frac{1}{k!} = e - 1$$
5. **Interpretation:** The series sums all reciprocals of factorials starting from \(k=1\), which converges to \(e - 1\).
**Final answer:**
$$\sum_{k=1}^\infty \frac{1}{k!} = e - 1$$
Infinite Factorial Series A92354
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