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 | 0 |
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 7 |
| 5 | 25 |
| 6 | 100 |
| 7 | 469 |
| 8 | 2481 |
| 9 | 14406 |
| 10 | 90995 |
| 11 | 621553 |
| 12 | 4561112 |
| 13 | 35736921 |
| 14 | 297435521 |
| 15 | 2618575194 |
| 16 | 24297706927 |
| 17 | 236870849417 |
| 18 | 2419213831452 |
| 19 | 25820011544781 |
| 20 | 287327296473585 |
| 21 | 3326999636488190 |
| 22 | 40011485288491131 |