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 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 20 |
| 5 | 74 |
| 6 | 302 |
| 7 | 1314 |
| 8 | 6122 |
| 9 | 29982 |
| 10 | 154718 |
| 11 | 831986 |
| 12 | 4667070 |
| 13 | 27118610 |
| 14 | 163264862 |
| 15 | 1013640242 |
| 16 | 6488705638 |
| 17 | 42687497378 |
| 18 | 288492113950 |
| 19 | 1998190669298 |
| 20 | 14177192483742 |
| 21 | 102856494496050 |
| 22 | 762657487965086 |
| 23 | 5771613810502002 |
| 24 | 44555989658479726 |
| 25 | 350503696871063138 |