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 | 3 |
| 2 | 9 |
| 3 | 30 |
| 4 | 103 |
| 5 | 366 |
| 6 | 1323 |
| 7 | 4859 |
| 8 | 18033 |
| 9 | 67531 |
| 10 | 254620 |
| 11 | 965592 |
| 12 | 3679039 |
| 13 | 14074126 |
| 14 | 54023919 |
| 15 | 207985518 |
| 16 | 802774173 |
| 17 | 3105514305 |
| 18 | 12037590980 |
| 19 | 46743091795 |
| 20 | 181796906808 |
| 21 | 708073498446 |
| 22 | 2761428873186 |
| 23 | 10782065189898 |
| 24 | 42144216934185 |