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 | 2 |
| 2 | 5 |
| 3 | 19 |
| 4 | 97 |
| 5 | 658 |
| 6 | 5458 |
| 7 | 53628 |
| 8 | 606871 |
| 9 | 7766312 |
| 10 | 110811174 |
| 11 | 1743359979 |
| 12 | 29972475254 |
| 13 | 558940415943 |
| 14 | 11235765584497 |
| 15 | 242168565186139 |
| 16 | 5570683131749362 |
| 17 | 136215122718876230 |
| 18 | 3527978807819506487 |
| 19 | 96480528944412962039 |
| 20 | 2778048842021042988465 |