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 | 3 |
| 3 | 10 |
| 4 | 44 |
| 5 | 231 |
| 6 | 1427 |
| 7 | 10151 |
| 8 | 81923 |
| 9 | 740732 |
| 10 | 7425042 |
| 11 | 81773715 |
| 12 | 981864897 |
| 13 | 12767876941 |
| 14 | 178774288331 |
| 15 | 2681781213130 |
| 16 | 42909715480460 |
| 17 | 729474427239587 |
| 18 | 13130613291110603 |
| 19 | 249482261007109579 |
| 20 | 4989650444408388515 |
| 21 | 104782705832468197252 |
| 22 | 2305219956684224457858 |