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 | 2 |
| 4 | 5 |
| 5 | 12 |
| 6 | 35 |
| 7 | 108 |
| 8 | 393 |
| 9 | 1666 |
| 10 | 8543 |
| 11 | 54190 |
| 12 | 436740 |
| 13 | 4565450 |
| 14 | 62930604 |
| 15 | 1156277748 |
| 16 | 28509174012 |
| 17 | 946786816168 |
| 18 | 42448800498744 |
| 19 | 2573207315483554 |
| 20 | 211180300735118954 |
| 21 | 23490473719472829824 |
| 22 | 3545759835559406756008 |
| 23 | 727077827560669587718290 |