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 | 6 |
| 4 | 18 |
| 5 | 54 |
| 6 | 166 |
| 7 | 514 |
| 8 | 1610 |
| 9 | 5078 |
| 10 | 16118 |
| 11 | 51394 |
| 12 | 164474 |
| 13 | 527798 |
| 14 | 1697254 |
| 15 | 5466498 |
| 16 | 17627370 |
| 17 | 56892246 |
| 18 | 183742358 |