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 | 1 |
| 3 | 2 |
| 4 | 20 |
| 5 | 1512 |
| 6 | 1513 |
| 7 | 1514 |
| 8 | 6320 |
| 9 | 6372 |
| 10 | 6373 |
| 11 | 6374 |
| 12 | 6500 |
| 13 | 15120 |
| 14 | 15121 |
| 15 | 15122 |
| 16 | 15302 |
| 17 | 40014 |
| 18 | 119096754 |
| 19 | 119096802 |
| 20 | 91547225622 |
| 21 | 91550794374 |