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 | 5 |
| 4 | 16 |
| 5 | 54 |
| 6 | 180 |
| 7 | 595 |
| 8 | 1964 |
| 9 | 6485 |
| 10 | 21418 |
| 11 | 70740 |
| 12 | 233640 |
| 13 | 771661 |
| 14 | 2548622 |
| 15 | 8417525 |
| 16 | 27801196 |
| 17 | 91821114 |
| 18 | 303264540 |
| 19 | 1001614735 |
| 20 | 3308108744 |
| 21 | 10925940965 |
| 22 | 36085931638 |
| 23 | 119183735880 |
| 24 | 393637139280 |
| 25 | 1300095153721 |
| 26 | 4293922600442 |