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 | 3 |
| 3 | 9 |
| 4 | 33 |
| 5 | 153 |
| 6 | 873 |
| 7 | 5913 |
| 8 | 46233 |
| 9 | 409113 |
| 10 | 4037913 |
| 11 | 43954713 |
| 12 | 522956313 |
| 13 | 6749977113 |
| 14 | 93928268313 |
| 15 | 1401602636313 |
| 16 | 22324392524313 |
| 17 | 378011820620313 |
| 18 | 6780385526348313 |
| 19 | 128425485935180313 |
| 20 | 2561327494111820313 |
| 21 | 53652269665821260313 |
| 22 | 1177652997443428940313 |