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 | 5 |
| 1 | 23 |
| 2 | 133 |
| 3 | 775 |
| 4 | 4517 |
| 5 | 26327 |
| 6 | 153445 |
| 7 | 894343 |
| 8 | 5212613 |
| 9 | 30381335 |
| 10 | 177075397 |
| 11 | 1032071047 |
| 12 | 6015350885 |
| 13 | 35060034263 |
| 14 | 204344854693 |
| 15 | 1191009093895 |
| 16 | 6941709708677 |
| 17 | 40459249158167 |
| 18 | 235813785240325 |
| 19 | 1374423462283783 |
| 20 | 8010726988462373 |
| 21 | 46689938468490455 |