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 | 1 |
| 2 | 4 |
| 3 | 12 |
| 4 | 24 |
| 5 | 630 |
| 6 | 84 |
| 7 | 117656 |
| 8 | 4176 |
| 9 | 531531 |
| 10 | 20020 |
| 11 | 25937424612 |
| 12 | 21192 |
| 13 | 23298085122494 |
| 14 | 15059100 |
| 15 | 2562941490 |
| 16 | 4295033120 |
| 17 | 48661191875666868498 |
| 18 | 68025132 |
| 19 | 104127350297911241532860 |
| 20 | 25600320440 |
| 21 | 7355827597153224 |
| 22 | 53119845582892 |
| 23 | 907846434775996175406740561352 |