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) |
|---|---|
| 4 | 1 |
| 5 | 3 |
| 6 | 9 |
| 7 | 31 |
| 8 | 105 |
| 9 | 351 |
| 10 | 1157 |
| 11 | 3755 |
| 12 | 12013 |
| 13 | 37951 |
| 14 | 118613 |
| 15 | 367383 |
| 16 | 1129345 |
| 17 | 3449823 |
| 18 | 10482869 |
| 19 | 31713863 |
| 20 | 95589753 |
| 21 | 287224199 |
| 22 | 860773781 |
| 23 | 2573894583 |
| 24 | 7681972113 |
| 25 | 22890634939 |
| 26 | 68116073369 |
| 27 | 202458285647 |
| 28 | 601159897137 |