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 | 1 |
| 1 | 1 |
| 2 | 5 |
| 3 | 52 |
| 4 | 451 |
| 5 | 3498 |
| 6 | 23502 |
| 7 | 173611 |
| 8 | 1323447 |
| 9 | 9920654 |
| 10 | 73573634 |
| 11 | 545170514 |
| 12 | 4060213800 |
| 13 | 30266880736 |
| 14 | 225316532881 |
| 15 | 1676398961171 |
| 16 | 12475867876511 |
| 17 | 92870049802057 |
| 18 | 691310371544378 |
| 19 | 5145544200921776 |
| 20 | 38298595223058076 |
| 21 | 285066094324142481 |
| 22 | 2121840794371117780 |