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 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 8 |
| 5 | 67 |
| 6 | 701 |
| 7 | 10047 |
| 8 | 218083 |
| 9 | 7758105 |
| 10 | 478466565 |
| 11 | 52762737260 |
| 12 | 10566937121191 |
| 13 | 3876933205880431 |
| 14 | 2621875289142578194 |
| 15 | 3285187439267316978728 |
| 16 | 7662096100649423384254265 |
| 17 | 33405651855362295512020765765 |
| 18 | 273319227135047244053866187609854 |