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 | 4 |
| 2 | 17 |
| 3 | 104 |
| 4 | 347 |
| 5 | 4132 |
| 6 | 50251 |
| 7 | 47248 |
| 8 | 848261 |
| 9 | 16882724 |
| 10 | 16189889 |
| 11 | 357817912 |
| 12 | 1856017421 |
| 13 | 5753962988 |
| 14 | 161845337077 |
| 15 | 4871637351712 |
| 16 | 5008383140437 |
| 17 | 5137314884092 |
| 18 | 185568039683479 |
| 19 | 181286844605704 |
| 20 | 7599727236867089 |