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 | 12 |
| 1 | 132 |
| 2 | 876 |
| 3 | 4416 |
| 4 | 18624 |
| 5 | 69060 |
| 6 | 232044 |
| 7 | 720648 |
| 8 | 2097612 |
| 9 | 5781120 |
| 10 | 15203904 |
| 11 | 38387556 |
| 12 | 93503052 |
| 13 | 220586244 |
| 14 | 505673280 |
| 15 | 1129518564 |
| 16 | 2464116480 |
| 17 | 5260683840 |
| 18 | 11010018840 |
| 19 | 22623235620 |
| 20 | 45700246668 |
| 21 | 90863466372 |
| 22 | 178000194348 |
| 23 | 343888491684 |
| 24 | 655760533632 |
| 25 | 1235186054724 |