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) |
|---|---|
| 2 | 1 |
| 3 | 3 |
| 4 | 9 |
| 5 | 35 |
| 6 | 201 |
| 7 | 1827 |
| 8 | 27337 |
| 9 | 692003 |
| 10 | 30251721 |
| 11 | 2320518947 |
| 12 | 316359580361 |
| 13 | 77477180493603 |
| 14 | 34394869942983369 |
| 15 | 27893897106768940835 |
| 16 | 41603705003444309596873 |
| 17 | 114788185359199234852802339 |
| 18 | 588880400923055731115178072777 |