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 | 1 |
| 1 | 18 |
| 2 | 121 |
| 3 | 859 |
| 4 | 15226 |
| 5 | 54070 |
| 6 | 1071206 |
| 7 | 3933314 |
| 8 | 34614430 |
| 9 | 309084622 |
| 10 | 2792083255 |
| 11 | 61496476037 |
| 12 | 1214237371612 |
| 13 | 5255429125063 |
| 14 | 105341326636887 |
| 15 | 458846460486827 |
| 16 | 15441107727480784 |
| 17 | 16660543186177748 |
| 18 | 832868428561305574 |
| 19 | 1494006786965549890 |
| 20 | 14206605445888164436 |
| 21 | 135418222271099812357 |