Brachylog, 6 bytes
g;?j₎×
Explanation
Example input: 5
g Group: [5]
;? Pair with the Input: [[5], 5]
j₎ Juxtapose [5] 5 times: [5, 5, 5, 5, 5]
× Multiply
Fatalize
- 39.3k
- 5
- 70
- 162