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 | 9 |
| 2 | 81 |
| 3 | 177 |
| 4 | 575 |
| 5 | 1360 |
| 6 | 3106 |
| 7 | 8652 |
| 8 | 22114 |
| 9 | 53620 |
| 10 | 139806 |
| 11 | 360132 |
| 12 | 899952 |
| 13 | 2300016 |
| 14 | 5898082 |
| 15 | 14925674 |
| 16 | 37975776 |
| 17 | 96993892 |
| 18 | 246541258 |
| 19 | 627068300 |
| 20 | 1598281686 |
| 21 | 4067781864 |
| 22 | 10349972204 |
| 23 | 26357799164 |
| 24 | 67101532924 |
| 25 | 170780094962 |