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 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 6 |
| 5 | 27 |
| 6 | 160 |
| 7 | 1189 |
| 8 | 10600 |
| 9 | 110161 |
| 10 | 1306629 |
| 11 | 17408293 |
| 12 | 257299241 |
| 13 | 4177017722 |
| 14 | 73872560359 |
| 15 | 1413560616317 |
| 16 | 29096001945172 |
| 17 | 641010535303531 |
| 18 | 15049350893772391 |
| 19 | 375084409475304164 |
| 20 | 9890697492431533299 |