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 | 17 |
| 3 | 33 |
| 4 | 305 |
| 5 | 833 |
| 6 | 5713 |
| 7 | 19041 |
| 8 | 110449 |
| 9 | 415105 |
| 10 | 2182289 |
| 11 | 8823969 |
| 12 | 43740593 |
| 13 | 184924097 |
| 14 | 884773585 |
| 15 | 3843559137 |
| 16 | 17999936497 |
| 17 | 79496882689 |
| 18 | 367495866641 |
| 19 | 1639445989665 |
| 20 | 7519379855921 |
| 21 | 33750515690561 |
| 22 | 154060593385297 |