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 | 24 |
| 2 | 288 |
| 3 | 2312 |
| 4 | 14016 |
| 5 | 68664 |
| 6 | 284000 |
| 7 | 1022760 |
| 8 | 3281280 |
| 9 | 9545560 |
| 10 | 25534368 |
| 11 | 63521352 |
| 12 | 148321344 |
| 13 | 327572856 |
| 14 | 688686048 |
| 15 | 1385794152 |
| 16 | 2681291520 |
| 17 | 5008112280 |
| 18 | 9060853280 |
| 19 | 15926230920 |
| 20 | 27266245056 |
| 21 | 45570869944 |
| 22 | 74501171808 |