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 | 1 |
| 3 | 1 |
| 4 | 3 |
| 5 | 6 |
| 6 | 18 |
| 7 | 44 |
| 8 | 129 |
| 9 | 354 |
| 10 | 1040 |
| 11 | 2961 |
| 12 | 8662 |
| 13 | 25022 |
| 14 | 73005 |
| 15 | 211723 |
| 16 | 616522 |
| 17 | 1789320 |
| 18 | 5203258 |
| 19 | 15097067 |