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 | 3 |
| 4 | 12 |
| 5 | 58 |
| 6 | 344 |
| 7 | 2405 |
| 8 | 19238 |
| 9 | 173138 |
| 10 | 1731378 |
| 11 | 19045154 |
| 12 | 228541845 |
| 13 | 2971043978 |
| 14 | 41594615682 |
| 15 | 623919235225 |
| 16 | 9982707763599 |
| 17 | 169706031981174 |
| 18 | 3054708575661119 |
| 19 | 58039462937561246 |
| 20 | 1160789258751224920 |
| 21 | 24376574433775723304 |
| 22 | 536284637543065912676 |