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 | 6 |
| 4 | 26 |
| 5 | 100 |
| 6 | 1096 |
| 7 | 3920 |
| 8 | 13936 |
| 9 | 16544 |
| 10 | 296256 |
| 11 | 1068672 |
| 12 | 11652352 |
| 13 | 42658304 |
| 14 | 1100471296 |
| 15 | 4079876096 |
| 16 | 15205967872 |
| 17 | 56939270144 |
| 18 | 642281037824 |
| 19 | 2423854317568 |
| 20 | 9177027411968 |
| 21 | 34846713511936 |
| 22 | 1459319692460032 |
| 23 | 5568939824513024 |
| 24 | 21297365878571008 |