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 | 0 |
| 2 | 3 |
| 3 | 22 |
| 4 | 146 |
| 5 | 970 |
| 6 | 6601 |
| 7 | 46012 |
| 8 | 328188 |
| 9 | 2387498 |
| 10 | 17666752 |
| 11 | 132631060 |
| 12 | 1008068661 |
| 13 | 7743145556 |
| 14 | 60019505338 |
| 15 | 468911161556 |
| 16 | 3688746483355 |
| 17 | 29194239490432 |
| 18 | 232297608127077 |
| 19 | 1857240493924050 |
| 20 | 14912570002666430 |
| 21 | 120202700216204324 |
| 22 | 972289121546949231 |