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) |
|---|---|
| 3 | 1 |
| 4 | 5 |
| 5 | 20 |
| 6 | 71 |
| 7 | 237 |
| 8 | 761 |
| 9 | 2377 |
| 10 | 7278 |
| 11 | 21945 |
| 12 | 65375 |
| 13 | 192861 |
| 14 | 564387 |
| 15 | 1640496 |
| 16 | 4741103 |
| 17 | 13634501 |
| 18 | 39042437 |
| 19 | 111379025 |
| 20 | 316687006 |
| 21 | 897796581 |
| 22 | 2538530615 |
| 23 | 7160768785 |
| 24 | 20156241155 |
| 25 | 56626360256 |
| 26 | 158804376883 |
| 27 | 444638710925 |
| 28 | 1243115597929 |
| 29 | 3470779612521 |
| 30 | 9678320566654 |