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) |
|---|---|
| 0 | 1 |
| 1 | 6 |
| 2 | 29 |
| 3 | 141 |
| 4 | 739 |
| 5 | 4276 |
| 6 | 27483 |
| 7 | 195978 |
| 8 | 1544074 |
| 9 | 13371684 |
| 10 | 126591212 |
| 11 | 1303252476 |
| 12 | 14517950305 |
| 13 | 174196495882 |
| 14 | 2241822436160 |
| 15 | 30826098464147 |
| 16 | 451299846525541 |
| 17 | 7012090426122158 |
| 18 | 115289977296253757 |
| 19 | 2000463474160276658 |