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 | 3 |
| 3 | 12 |
| 4 | 44 |
| 5 | 144 |
| 6 | 432 |
| 7 | 1216 |
| 8 | 3264 |
| 9 | 8448 |
| 10 | 21248 |
| 11 | 52224 |
| 12 | 125952 |
| 13 | 299008 |
| 14 | 700416 |
| 15 | 1622016 |
| 16 | 3719168 |
| 17 | 8454144 |
| 18 | 19070976 |
| 19 | 42729472 |
| 20 | 95158272 |
| 21 | 210763776 |
| 22 | 464519168 |
| 23 | 1019215872 |
| 24 | 2227175424 |
| 25 | 4848615424 |
| 26 | 10519314432 |
| 27 | 22749904896 |
| 28 | 49056579584 |
| 29 | 105495134208 |
| 30 | 226291089408 |