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) |
|---|---|
| 1 | 9 |
| 2 | 81 |
| 3 | 289 |
| 4 | 900 |
| 5 | 3249 |
| 6 | 11449 |
| 7 | 42436 |
| 8 | 157609 |
| 9 | 597529 |
| 10 | 2280100 |
| 11 | 8791225 |
| 12 | 34093921 |
| 13 | 133033156 |
| 14 | 521345889 |
| 15 | 2051093521 |
| 16 | 8093881156 |
| 17 | 32021313025 |
| 18 | 126943276681 |
| 19 | 504097160004 |
| 20 | 2004526450969 |
| 21 | 7979839669321 |
| 22 | 31795772223076 |
| 23 | 126783929266569 |