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 | 3 |
| 2 | 12 |
| 3 | 69 |
| 4 | 560 |
| 5 | 6059 |
| 6 | 83215 |
| 7 | 1399161 |
| 8 | 28020221 |
| 9 | 654110586 |
| 10 | 17494347067 |
| 11 | 528556017365 |
| 12 | 17830841841940 |
| 13 | 665126088764191 |
| 14 | 27208111182653865 |
| 15 | 1211942062741823574 |
| 16 | 58424831462907214924 |
| 17 | 3031993693950136247986 |