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 | 2 |
| 1 | 20 |
| 2 | 143 |
| 3 | 986 |
| 4 | 6764 |
| 5 | 46367 |
| 6 | 317810 |
| 7 | 2178308 |
| 8 | 14930351 |
| 9 | 102334154 |
| 10 | 701408732 |
| 11 | 4807526975 |
| 12 | 32951280098 |
| 13 | 225851433716 |
| 14 | 1548008755919 |
| 15 | 10610209857722 |
| 16 | 72723460248140 |
| 17 | 498454011879263 |
| 18 | 3416454622906706 |
| 19 | 23416728348467684 |
| 20 | 160500643816367087 |
| 21 | 1100087778366101930 |