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 | 169 |
| 4 | 441 |
| 5 | 1225 |
| 6 | 2809 |
| 7 | 6241 |
| 8 | 14161 |
| 9 | 31329 |
| 10 | 68121 |
| 11 | 148225 |
| 12 | 321489 |
| 13 | 693889 |
| 14 | 1495729 |
| 15 | 3222025 |
| 16 | 6932689 |
| 17 | 14907321 |
| 18 | 32046921 |
| 19 | 68873401 |
| 20 | 147987225 |
| 21 | 317944561 |
| 22 | 683038225 |
| 23 | 1467273025 |
| 24 | 3151811881 |
| 25 | 6770162961 |
| 26 | 14542189281 |
| 27 | 31235967169 |