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 | 6 |
| 2 | 15 |
| 3 | 44 |
| 4 | 141 |
| 5 | 480 |
| 6 | 1703 |
| 7 | 6216 |
| 8 | 23136 |
| 9 | 87334 |
| 10 | 333309 |
| 11 | 1283706 |
| 12 | 4982458 |
| 13 | 19466130 |
| 14 | 76479612 |
| 15 | 301923554 |
| 16 | 1196919714 |
| 17 | 4762524162 |
| 18 | 19012433694 |