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 | 4 |
| 2 | 132 |
| 3 | 264 |
| 4 | 1872 |
| 5 | 6820 |
| 6 | 31420 |
| 7 | 123826 |
| 8 | 515268 |
| 9 | 2058802 |
| 10 | 8332796 |
| 11 | 33350162 |
| 12 | 133891940 |
| 13 | 535789038 |
| 14 | 2145632584 |
| 15 | 8584207782 |
| 16 | 34349419412 |
| 17 | 137408677592 |
| 18 | 549699224224 |
| 19 | 2198863697876 |
| 20 | 8795786194236 |
| 21 | 35183533311476 |
| 22 | 140735839290104 |