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 | 18 |
| 2 | 324 |
| 3 | 1014 |
| 4 | 3513 |
| 5 | 14184 |
| 6 | 45520 |
| 7 | 135686 |
| 8 | 417772 |
| 9 | 1253238 |
| 10 | 3651096 |
| 11 | 10647801 |
| 12 | 30923564 |
| 13 | 88853464 |
| 14 | 254267485 |
| 15 | 725590642 |
| 16 | 2060214105 |
| 17 | 5827339605 |
| 18 | 16437397037 |
| 19 | 46220378910 |
| 20 | 129590864085 |
| 21 | 362487844504 |
| 22 | 1011664530775 |
| 23 | 2817477642474 |