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 | 2 |
| 3 | 4 |
| 4 | 12 |
| 5 | 38 |
| 6 | 136 |
| 7 | 490 |
| 8 | 1852 |
| 9 | 7108 |
| 10 | 27880 |
| 11 | 110892 |
| 12 | 447060 |
| 13 | 1821252 |
| 14 | 7489732 |
| 15 | 31045350 |
| 16 | 129587996 |
| 17 | 544228664 |
| 18 | 2298008824 |
| 19 | 9750218012 |
| 20 | 41548438040 |
| 21 | 177740526076 |
| 22 | 763046178960 |
| 23 | 3286318131646 |
| 24 | 14195239150556 |
| 25 | 61481540391722 |