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) |
|---|---|
| 3 | 1 |
| 4 | 4 |
| 5 | 26 |
| 6 | 281 |
| 7 | 3602 |
| 8 | 56550 |
| 9 | 1121538 |
| 10 | 26193063 |
| 11 | 693887458 |
| 12 | 20808594004 |
| 13 | 699641607622 |
| 14 | 26001947464541 |
| 15 | 1059148042622186 |
| 16 | 47015706166302146 |
| 17 | 2260884753582320442 |
| 18 | 117153802097975691651 |
| 19 | 6513779162975806691634 |