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) |
|---|---|
| 2 | 1 |
| 3 | 2 |
| 4 | 13 |
| 5 | 42 |
| 6 | 225 |
| 7 | 802 |
| 8 | 4235 |
| 9 | 15478 |
| 10 | 82425 |
| 11 | 304156 |
| 12 | 1634435 |
| 13 | 6064389 |
| 14 | 32819839 |
| 15 | 122244344 |
| 16 | 665162897 |
| 17 | 2484851486 |
| 18 | 13577768505 |
| 19 | 50841782786 |
| 20 | 278745377821 |
| 21 | 1045763359942 |
| 22 | 5749240499515 |
| 23 | 21603797860416 |
| 24 | 119040956286133 |
| 25 | 447922312642212 |
| 26 | 2472886893122590 |
| 27 | 9315646385012666 |
| 28 | 51514464212546865 |
| 29 | 194255376492836212 |