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 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 7 |
| 5 | 36 |
| 6 | 245 |
| 7 | 2076 |
| 8 | 21059 |
| 9 | 248836 |
| 10 | 3356609 |
| 11 | 50896380 |
| 12 | 856958911 |
| 13 | 15864014388 |
| 14 | 320245960333 |
| 15 | 7001257954796 |
| 16 | 164792092647355 |
| 17 | 4154906594518116 |
| 18 | 111719929072986521 |
| 19 | 3191216673497748444 |