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 | 1 |
| 3 | 2 |
| 4 | 4 |
| 5 | 12 |
| 6 | 40 |
| 7 | 154 |
| 8 | 659 |
| 9 | 3085 |
| 10 | 15438 |
| 11 | 81200 |
| 12 | 442206 |
| 13 | 2465945 |
| 14 | 13968206 |
| 15 | 79933735 |
| 16 | 460447075 |
| 17 | 2663586832 |
| 18 | 15450089345 |
| 19 | 89773528848 |
| 20 | 522212524474 |