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 | 1 |
| 2 | 2 |
| 3 | 3 |
| 4 | 40 |
| 5 | 185 |
| 6 | 3936 |
| 7 | 35917 |
| 8 | 978160 |
| 9 | 14301513 |
| 10 | 464105440 |
| 11 | 9648558161 |
| 12 | 361181788584 |
| 13 | 9884595572293 |
| 14 | 419174374377136 |
| 15 | 14317833123918885 |
| 16 | 679698565575210976 |
| 17 | 27884513269105178033 |
| 18 | 1468696946887669701312 |