Write outer electronic configuration of lanthanoids.

Explanation

To determine the outer electronic configuration of lanthanoids, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Lanthanoids**:
- Lanthanoids are a series of 15 elements from Lanthanum (La, atomic number 57) to Lutetium (Lu, atomic number 71).

2. **Understand the Electron Configuration**:
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