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 | 25 |
| 2 | 625 |
| 3 | 2141 |
| 4 | 6217 |
| 5 | 21991 |
| 6 | 73325 |
| 7 | 268275 |
| 8 | 959855 |
| 9 | 3607311 |
| 10 | 13436035 |
| 11 | 51497695 |
| 12 | 196706551 |
| 13 | 765001527 |
| 14 | 2972743953 |
| 15 | 11691712763 |
| 16 | 46007927815 |
| 17 | 182581500547 |
| 18 | 725456035227 |
| 19 | 2900274648193 |
| 20 | 11612610826251 |
| 21 | 46711361492143 |