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 | 840 |
| 2 | 95802 |
| 3 | 3504816 |
| 4 | 55350120 |
| 5 | 465944304 |
| 6 | 2610853840 |
| 7 | 11337146784 |
| 8 | 40208417466 |
| 9 | 123411903160 |
| 10 | 335056780464 |
| 11 | 830096613360 |
| 12 | 1893781702512 |
| 13 | 4058779021584 |
| 14 | 8190877926720 |
| 15 | 15805879161632 |
| 16 | 29122237029480 |
| 17 | 51905458442208 |
| 18 | 89163973663338 |
| 19 | 149313692762640 |
| 20 | 242598110651568 |