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 | 4 |
| 4 | 13 |
| 5 | 31 |
| 6 | 70 |
| 7 | 169 |
| 8 | 421 |
| 9 | 1036 |
| 10 | 2521 |
| 11 | 6139 |
| 12 | 14998 |
| 13 | 36661 |
| 14 | 89545 |
| 15 | 218644 |
| 16 | 533941 |
| 17 | 1304071 |
| 18 | 3184966 |
| 19 | 7778449 |
| 20 | 18996733 |
| 21 | 46394716 |
| 22 | 113307745 |
| 23 | 276726019 |
| 24 | 675833686 |
| 25 | 1650553981 |
| 26 | 4031064961 |
| 27 | 9844867684 |
| 28 | 24043624093 |
| 29 | 58720529071 |