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) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 16 |
| 3 | 289 |
| 4 | 5184 |
| 5 | 93025 |
| 6 | 1669264 |
| 7 | 29953729 |
| 8 | 537497856 |
| 9 | 9645007681 |
| 10 | 173072640400 |
| 11 | 3105662519521 |
| 12 | 55728852710976 |
| 13 | 1000013686278049 |
| 14 | 17944517500293904 |
| 15 | 322001301319012225 |
| 16 | 5778078906241926144 |
| 17 | 103683419011035658369 |
| 18 | 1860523463292399924496 |
| 19 | 33385738920252162982561 |