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 | 0 |
| 3 | 0 |
| 4 | 25 |
| 5 | 472 |
| 6 | 6185 |
| 7 | 70700 |
| 8 | 759045 |
| 9 | 7894992 |
| 10 | 80736625 |
| 11 | 817897300 |
| 12 | 8241325565 |
| 13 | 82783813112 |
| 14 | 830046591465 |
| 15 | 8313655213500 |
| 16 | 83215436364085 |
| 17 | 832626645756832 |
| 18 | 8329096006484705 |
| 19 | 83307920631515300 |
| 20 | 833180902353754605 |
| 21 | 8332418928963358152 |
| 22 | 83327847634888960345 |