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) |
|---|---|
| 2 | 1 |
| 3 | 31 |
| 4 | 381 |
| 5 | 3431 |
| 6 | 26769 |
| 7 | 193705 |
| 8 | 1343521 |
| 9 | 9091270 |
| 10 | 60632419 |
| 11 | 401001030 |
| 12 | 2639871326 |
| 13 | 17339260251 |
| 14 | 113792427233 |
| 15 | 746807661549 |
| 16 | 4903854042841 |
| 17 | 32227106641988 |
| 18 | 211992209767971 |
| 19 | 1395903036647155 |
| 20 | 9200826759772935 |