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 | 1 |
| 2 | 1 |
| 3 | 5 |
| 4 | 13 |
| 5 | 25 |
| 6 | 57 |
| 7 | 141 |
| 8 | 325 |
| 9 | 737 |
| 10 | 1713 |
| 11 | 3989 |
| 12 | 9213 |
| 13 | 21289 |
| 14 | 49321 |
| 15 | 114205 |
| 16 | 264245 |
| 17 | 611569 |
| 18 | 1415713 |
| 19 | 3276837 |
| 20 | 7584237 |
| 21 | 17554489 |
| 22 | 40632089 |
| 23 | 94046637 |
| 24 | 217679141 |
| 25 | 503840001 |
| 26 | 1166187409 |
| 27 | 2699251381 |
| 28 | 6247675357 |
| 29 | 14460848969 |
| 30 | 33471028105 |