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 | 21 |
| 2 | 165 |
| 3 | 1287 |
| 4 | 19448 |
| 5 | 75582 |
| 6 | 1144066 |
| 7 | 51895935 |
| 8 | 141120525 |
| 9 | 6107086800 |
| 10 | 7898654920 |
| 11 | 15338678264 |
| 12 | 5178066751 |
| 13 | 266783135710 |
| 14 | 109712808959985 |
| 15 | 22512762077400 |
| 16 | 97862516286480 |
| 17 | 12802736917880 |
| 18 | 18385569737808 |