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) |
|---|---|
| 4 | 1 |
| 5 | 16 |
| 6 | 181 |
| 7 | 1821 |
| 8 | 17557 |
| 9 | 167449 |
| 10 | 1604098 |
| 11 | 15555398 |
| 12 | 153315999 |
| 13 | 1538907306 |
| 14 | 15743413076 |
| 15 | 164161815768 |
| 16 | 1744049683213 |
| 17 | 18865209953045 |
| 18 | 207591285198178 |
| 19 | 2321616416280982 |
| 20 | 26362085777156567 |
| 21 | 303635722412859447 |
| 22 | 3544040394934246209 |
| 23 | 41881891423602685193 |