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 | 6 |
| 4 | 20 |
| 5 | 73 |
| 6 | 281 |
| 7 | 1124 |
| 8 | 4627 |
| 9 | 19474 |
| 10 | 83421 |
| 11 | 362528 |
| 12 | 1594389 |
| 13 | 7083078 |
| 14 | 31738724 |
| 15 | 143281473 |
| 16 | 651048571 |
| 17 | 2975243348 |
| 18 | 13665866849 |
| 19 | 63055369522 |
| 20 | 292130900461 |
| 21 | 1358415528683 |
| 22 | 6337824891559 |
| 23 | 29660089051015 |
| 24 | 139193062791189 |
| 25 | 654903798282528 |
| 26 | 3088627236146085 |