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 | 4 |
| 3 | 12 |
| 4 | 44 |
| 5 | 170 |
| 6 | 936 |
| 7 | 7308 |
| 8 | 98768 |
| 9 | 2472012 |
| 10 | 120051680 |
| 11 | 11208976504 |
| 12 | 1981094071104 |
| 13 | 656526407783376 |
| 14 | 406758179201296832 |
| 15 | 471397289547064631520 |
| 16 | 1024016251272440926318848 |
| 17 | 4180909690610059855623236192 |
| 18 | 32176399052621010609861807435264 |