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 | 1 |
| 2 | 5 |
| 3 | 23 |
| 4 | 104 |
| 5 | 469 |
| 6 | 2119 |
| 7 | 9607 |
| 8 | 43727 |
| 9 | 199819 |
| 10 | 916631 |
| 11 | 4220267 |
| 12 | 19497608 |
| 13 | 90370622 |
| 14 | 420136173 |
| 15 | 1958787580 |
| 16 | 9156770130 |
| 17 | 42912496696 |
| 18 | 201579245739 |
| 19 | 949002525067 |
| 20 | 4477049676288 |
| 21 | 21162505063028 |
| 22 | 100217666089863 |
| 23 | 475421115762173 |