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 | 12 |
| 4 | 51 |
| 5 | 259 |
| 6 | 1284 |
| 7 | 6665 |
| 8 | 34938 |
| 9 | 186624 |
| 10 | 1007510 |
| 11 | 5496925 |
| 12 | 30231792 |
| 13 | 167444795 |
| 14 | 932900050 |
| 15 | 5224277604 |
| 16 | 29386526544 |
| 17 | 165947641615 |
| 18 | 940369782528 |
| 19 | 5345260877285 |
| 20 | 30467985992745 |
| 21 | 174102782860140 |
| 22 | 997134114520250 |