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 | 4 |
| 4 | 13 |
| 5 | 38 |
| 6 | 141 |
| 7 | 515 |
| 8 | 2043 |
| 9 | 8176 |
| 10 | 33706 |
| 11 | 140471 |
| 12 | 593705 |
| 13 | 2531933 |
| 14 | 10893811 |
| 15 | 47202599 |
| 16 | 205843902 |
| 17 | 902644191 |
| 18 | 3977976135 |
| 19 | 17609163491 |