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 | 0 |
| 1 | 2 |
| 2 | 5 |
| 3 | 22 |
| 4 | 128 |
| 5 | 896 |
| 6 | 7220 |
| 7 | 65336 |
| 8 | 653720 |
| 9 | 7155104 |
| 10 | 84998768 |
| 11 | 1089232160 |
| 12 | 14981704736 |
| 13 | 220233312896 |
| 14 | 3447195190592 |
| 15 | 57261708795776 |
| 16 | 1006401042534272 |
| 17 | 18663532970127872 |
| 18 | 364283224523605760 |
| 19 | 7466218532765196800 |