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) |
|---|---|
| 1 | 7 |
| 2 | 40 |
| 3 | 64 |
| 4 | 400 |
| 5 | 632 |
| 6 | 1287 |
| 7 | 4000 |
| 8 | 40000 |
| 9 | 126712 |
| 10 | 209775 |
| 11 | 400000 |
| 12 | 646232 |
| 13 | 663367 |
| 14 | 4000000 |
| 15 | 40000000 |
| 16 | 75897600 |
| 17 | 213645607 |
| 18 | 400000000 |
| 19 | 4000000000 |
| 20 | 12713841912 |
| 21 | 40000000000 |
| 22 | 400000000000 |
| 23 | 749506541784 |
| 24 | 4000000000000 |
| 25 | 20397451214712 |