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 | 2 |
| 3 | 5 |
| 4 | 16 |
| 5 | 53 |
| 6 | 206 |
| 7 | 757 |
| 8 | 2780 |
| 9 | 10481 |
| 10 | 39898 |
| 11 | 146981 |
| 12 | 531752 |
| 13 | 1939885 |
| 14 | 7397846 |
| 15 | 29864213 |
| 16 | 122842036 |
| 17 | 488455217 |
| 18 | 1830814610 |
| 19 | 6508723141 |
| 20 | 22667908448 |
| 21 | 81343971941 |
| 22 | 312864734302 |
| 23 | 1280329420085 |
| 24 | 5332923123596 |
| 25 | 21687872072113 |
| 26 | 84397157118026 |
| 27 | 313673593771877 |