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 | 2 |
| 2 | 10 |
| 3 | 84 |
| 4 | 788 |
| 5 | 8188 |
| 6 | 90110 |
| 7 | 1035456 |
| 8 | 12269932 |
| 9 | 148886048 |
| 10 | 1840585914 |
| 11 | 23099713808 |
| 12 | 293535000452 |
| 13 | 3769200628592 |
| 14 | 48831588116862 |
| 15 | 637501117219024 |
| 16 | 8378367468484212 |
| 17 | 110760388293651950 |
| 18 | 1471854299855109782 |
| 19 | 19649723961974718686 |
| 20 | 263422552838889748560 |