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 | 1 |
| 3 | 2 |
| 4 | 3 |
| 5 | 5 |
| 6 | 7 |
| 7 | 16 |
| 8 | 41 |
| 9 | 135 |
| 10 | 632 |
| 11 | 4091 |
| 12 | 37020 |
| 13 | 478852 |
| 14 | 8897512 |
| 15 | 240133480 |
| 16 | 9489055662 |
| 17 | 552854898873 |
| 18 | 47794151866058 |
| 19 | 6165361571608551 |
| 20 | 1192709563056788508 |
| 21 | 347571453153709529743 |
| 22 | 153189847887607116894958 |