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 | 5 |
| 2 | 20 |
| 3 | 76 |
| 4 | 286 |
| 5 | 1078 |
| 6 | 4081 |
| 7 | 15521 |
| 8 | 59279 |
| 9 | 227239 |
| 10 | 873885 |
| 11 | 3370029 |
| 12 | 13027729 |
| 13 | 50469889 |
| 14 | 195892564 |
| 15 | 761615284 |
| 16 | 2965576714 |
| 17 | 11563073314 |
| 18 | 45141073924 |
| 19 | 176423482324 |
| 20 | 690215089744 |
| 21 | 2702831489824 |
| 22 | 10593202603774 |
| 23 | 41550902139550 |
| 24 | 163099562175850 |
| 25 | 640650742051802 |