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) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 12 |
| 4 | 146 |
| 5 | 3060 |
| 6 | 101642 |
| 7 | 5106612 |
| 8 | 377403266 |
| 9 | 40299722580 |
| 10 | 6138497261882 |
| 11 | 1320327172853172 |
| 12 | 397571105288091506 |
| 13 | 166330355795371103700 |
| 14 | 96036130723851671469482 |
| 15 | 76070282980382554147600692 |
| 16 | 82226869197428315925408327266 |
| 17 | 120722306604121583767045993825620 |
| 18 | 239727397782668638856762574296226842 |