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 | 15 |
| 3 | 136 |
| 4 | 1998 |
| 5 | 41973 |
| 6 | 1166263 |
| 7 | 40747561 |
| 8 | 1726907675 |
| 9 | 86421647389 |
| 10 | 5002021986418 |
| 11 | 329382745551946 |
| 12 | 24351172588548270 |
| 13 | 1999205882982496161 |
| 14 | 180613538916429940159 |
| 15 | 17817366508243503227269 |