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 | 1 |
| 3 | 8 |
| 4 | 122 |
| 5 | 2676 |
| 6 | 75197 |
| 7 | 2548336 |
| 8 | 100461956 |
| 9 | 4500071172 |
| 10 | 225305924896 |
| 11 | 12456434569184 |
| 12 | 753380353835754 |
| 13 | 49473301917640864 |
| 14 | 3505613955205438686 |
| 15 | 266627715169575108168 |
| 16 | 21667902182055638829520 |
| 17 | 1873978995774161192935320 |
| 18 | 171874439346918445003163152 |