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 | 2 |
| 3 | 5 |
| 4 | 12 |
| 5 | 30 |
| 6 | 91 |
| 7 | 256 |
| 8 | 823 |
| 9 | 2656 |
| 10 | 9103 |
| 11 | 31876 |
| 12 | 116113 |
| 13 | 432824 |
| 14 | 1659692 |
| 15 | 6508521 |
| 16 | 26112327 |
| 17 | 106927561 |
| 18 | 446654187 |
| 19 | 1900858001 |
| 20 | 8236367607 |
| 21 | 36306790636 |
| 22 | 162724173883 |
| 23 | 741105774720 |
| 24 | 3428164417401 |
| 25 | 16099059101049 |
| 26 | 76722208278328 |
| 27 | 370903316203353 |
| 28 | 1818316254655097 |