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 | 0 |
| 2 | 1 |
| 3 | 16 |
| 4 | 121 |
| 5 | 676 |
| 6 | 3249 |
| 7 | 14400 |
| 8 | 61009 |
| 9 | 252004 |
| 10 | 1026169 |
| 11 | 4145296 |
| 12 | 16670889 |
| 13 | 66879684 |
| 14 | 267944161 |
| 15 | 1072693504 |
| 16 | 4292739361 |
| 17 | 17175150916 |
| 18 | 68709515625 |
| 19 | 274856935824 |
| 20 | 1099467588025 |
| 21 | 4397954236900 |
| 22 | 17591993106961 |
| 23 | 70368341525056 |
| 24 | 281474137850481 |
| 25 | 1125898162012836 |