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 | 0 |
| 2 | 1 |
| 3 | 2 |
| 4 | 8 |
| 5 | 48 |
| 6 | 328 |
| 7 | 2335 |
| 8 | 17133 |
| 9 | 128262 |
| 10 | 975547 |
| 11 | 7518282 |
| 12 | 58582564 |
| 13 | 460769228 |
| 14 | 3653385453 |
| 15 | 29170737927 |
| 16 | 234350263419 |
| 17 | 1892956305974 |
| 18 | 15364355580327 |
| 19 | 125247311808502 |
| 20 | 1024983176867450 |
| 21 | 8417817643684208 |
| 22 | 69355110426227296 |