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 | 0 |
| 1 | 0 |
| 2 | 28 |
| 3 | 44 |
| 4 | 168 |
| 5 | 612 |
| 6 | 2520 |
| 7 | 10356 |
| 8 | 44712 |
| 9 | 195120 |
| 10 | 868224 |
| 11 | 3905388 |
| 12 | 17756424 |
| 13 | 81376140 |
| 14 | 375603480 |
| 15 | 1743843924 |
| 16 | 8138028696 |
| 17 | 38146891320 |
| 18 | 179515196280 |
| 19 | 847710124128 |
| 20 | 4015470916296 |
| 21 | 19073484584388 |
| 22 | 90826125756552 |
| 23 | 433488317523588 |
| 24 | 2073205037124648 |