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) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 4 |
| 4 | 8 |
| 5 | 24 |
| 6 | 52 |
| 7 | 136 |
| 8 | 296 |
| 9 | 720 |
| 10 | 1556 |
| 11 | 3624 |
| 12 | 7768 |
| 13 | 17584 |
| 14 | 37416 |
| 15 | 83024 |
| 16 | 175568 |
| 17 | 383904 |
| 18 | 807604 |
| 19 | 1746280 |
| 20 | 3657464 |
| 21 | 7839216 |
| 22 | 16357496 |
| 23 | 34812144 |
| 24 | 72407728 |
| 25 | 153204064 |
| 26 | 317777032 |
| 27 | 669108496 |
| 28 | 1384524656 |
| 29 | 2903267040 |
| 30 | 5994736336 |