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 | 0 |
| 3 | 0 |
| 4 | 2 |
| 5 | 8 |
| 6 | 26 |
| 7 | 79 |
| 8 | 232 |
| 9 | 664 |
| 10 | 1856 |
| 11 | 5072 |
| 12 | 13568 |
| 13 | 35584 |
| 14 | 91648 |
| 15 | 232192 |
| 16 | 579584 |
| 17 | 1427456 |
| 18 | 3473408 |
| 19 | 8359936 |
| 20 | 19922944 |
| 21 | 47054848 |
| 22 | 110231552 |
| 23 | 256311296 |
| 24 | 591921152 |
| 25 | 1358430208 |
| 26 | 3099590656 |
| 27 | 7034896384 |
| 28 | 15888023552 |
| 29 | 35718692864 |
| 30 | 79960211456 |
| 31 | 178291474432 |
| 32 | 396076515328 |
| 33 | 876844417024 |