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 | 7 |
| 3 | 42 |
| 4 | 234 |
| 5 | 1264 |
| 6 | 6776 |
| 7 | 36094 |
| 8 | 190560 |
| 9 | 997774 |
| 10 | 5199588 |
| 11 | 27025854 |
| 12 | 140092710 |
| 13 | 723510594 |
| 14 | 3720320512 |
| 15 | 19044051770 |
| 16 | 97051434120 |
| 17 | 492383872912 |
| 18 | 2486705768206 |