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 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 2 |
| 5 | 8 |
| 6 | 4 |
| 7 | 28 |
| 8 | 18 |
| 9 | 120 |
| 10 | 60 |
| 11 | 888 |
| 12 | 252 |
| 13 | 5220 |
| 14 | 1860 |
| 15 | 22224 |
| 16 | 9552 |
| 17 | 311088 |
| 18 | 59616 |
| 19 | 2473056 |
| 20 | 565920 |
| 21 | 13627008 |
| 22 | 4051872 |
| 23 | 235039392 |
| 24 | 33805440 |
| 25 | 1932037632 |
| 26 | 465239808 |
| 27 | 20604487680 |
| 28 | 4294865664 |
| 29 | 386228795904 |
| 30 | 35413136640 |