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 | 0 |
| 2 | 2 |
| 3 | 8 |
| 4 | 28 |
| 5 | 96 |
| 6 | 328 |
| 7 | 1120 |
| 8 | 3824 |
| 9 | 13056 |
| 10 | 44576 |
| 11 | 152192 |
| 12 | 519616 |
| 13 | 1774080 |
| 14 | 6057088 |
| 15 | 20680192 |
| 16 | 70606592 |
| 17 | 241065984 |
| 18 | 823050752 |
| 19 | 2810071040 |
| 20 | 9594182656 |
| 21 | 32756588544 |
| 22 | 111837988864 |
| 23 | 381838778368 |
| 24 | 1303679135744 |