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 | 0 |
| 2 | 2 |
| 3 | 4 |
| 4 | 12 |
| 5 | 16 |
| 6 | 76 |
| 7 | 128 |
| 8 | 386 |
| 9 | 832 |
| 10 | 2368 |
| 11 | 5024 |
| 12 | 13946 |
| 13 | 31680 |
| 14 | 82632 |
| 15 | 193696 |
| 16 | 498174 |
| 17 | 1182464 |
| 18 | 2993384 |
| 19 | 7213648 |
| 20 | 18061074 |
| 21 | 43832960 |
| 22 | 109163384 |
| 23 | 266217472 |
| 24 | 660116398 |
| 25 | 1615451648 |
| 26 | 3995295112 |
| 27 | 9796774896 |
| 28 | 24189684402 |
| 29 | 59396496000 |
| 30 | 146494223160 |
| 31 | 360026507808 |