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 | 3 |
| 3 | 10 |
| 4 | 70 |
| 5 | 708 |
| 6 | 15224 |
| 7 | 544152 |
| 8 | 39576432 |
| 9 | 5074417616 |
| 10 | 1296033011648 |
| 11 | 604178966756320 |
| 12 | 556052774253161600 |
| 13 | 954895322019762585664 |
| 14 | 3224152068625567826724224 |
| 15 | 20610090531322819956330186112 |