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 | 0 |
| 1 | 4 |
| 2 | 14 |
| 3 | 64 |
| 4 | 314 |
| 5 | 2814 |
| 6 | 2814 |
| 7 | 2814 |
| 8 | 237189 |
| 9 | 1018439 |
| 10 | 1018439 |
| 11 | 10784064 |
| 12 | 10784064 |
| 13 | 743205939 |
| 14 | 1963909064 |
| 15 | 20274455939 |
| 16 | 142344768439 |
| 17 | 142344768439 |
| 18 | 142344768439 |
| 19 | 7771739299689 |
| 20 | 64992198284064 |
| 21 | 446461924846564 |
| 22 | 1876973399455939 |
| 23 | 4261159190471564 |
| 24 | 16182088145549689 |
| 25 | 16182088145549689 |