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 | 2 |
| 2 | 126 |
| 3 | 4412 |
| 4 | 108220 |
| 5 | 2049770 |
| 6 | 31674678 |
| 7 | 413820584 |
| 8 | 4687156248 |
| 9 | 46894786710 |
| 10 | 420487598410 |
| 11 | 3418440803052 |
| 12 | 25437258929836 |
| 13 | 174630760523102 |
| 14 | 1113521228343010 |
| 15 | 6633053884912560 |
| 16 | 37097838553993648 |
| 17 | 195668363575483134 |
| 18 | 977073310632294978 |
| 19 | 4635352353992402420 |