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 | 7 |
| 3 | 20 |
| 4 | 55 |
| 5 | 148 |
| 6 | 403 |
| 7 | 1097 |
| 8 | 2981 |
| 9 | 8103 |
| 10 | 22026 |
| 11 | 59874 |
| 12 | 162755 |
| 13 | 442413 |
| 14 | 1202604 |
| 15 | 3269017 |
| 16 | 8886111 |
| 17 | 24154953 |
| 18 | 65659969 |
| 19 | 178482301 |
| 20 | 485165195 |
| 21 | 1318815734 |
| 22 | 3584912846 |
| 23 | 9744803446 |
| 24 | 26489122130 |
| 25 | 72004899337 |
| 26 | 195729609429 |
| 27 | 532048240602 |
| 28 | 1446257064291 |
| 29 | 3931334297144 |
| 30 | 10686474581524 |