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 | 0 |
| 1 | 1 |
| 2 | 2 |
| 3 | 7 |
| 4 | 16 |
| 5 | 46 |
| 6 | 110 |
| 7 | 295 |
| 8 | 720 |
| 9 | 1870 |
| 10 | 4612 |
| 11 | 11782 |
| 12 | 29224 |
| 13 | 73984 |
| 14 | 184102 |
| 15 | 463687 |
| 16 | 1156000 |
| 17 | 2902870 |
| 18 | 7245020 |
| 19 | 18161170 |
| 20 | 45356736 |
| 21 | 113576596 |
| 22 | 283765132 |
| 23 | 710118262 |
| 24 | 1774619616 |
| 25 | 4439253196 |
| 26 | 11095532840 |
| 27 | 27749232700 |
| 28 | 69363052600 |