This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 25 |
| 3 | 75 |
| 4 | 625 |
| 5 | 1875 |
| 6 | 15625 |
| 7 | 46875 |
| 8 | 390625 |
| 9 | 1171875 |
| 10 | 9765625 |
| 11 | 29296875 |
| 12 | 244140625 |
| 13 | 732421875 |
| 14 | 6103515625 |
| 15 | 18310546875 |
| 16 | 152587890625 |
| 17 | 457763671875 |
| 18 | 3814697265625 |
| 19 | 11444091796875 |
| 20 | 95367431640625 |
| 21 | 286102294921875 |