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 | 18 |
| 4 | 62 |
| 5 | 210 |
| 6 | 666 |
| 7 | 2063 |
| 8 | 6226 |
| 9 | 18484 |
| 10 | 54100 |
| 11 | 156620 |
| 12 | 449268 |
| 13 | 1278981 |
| 14 | 3617544 |
| 15 | 10175590 |
| 16 | 28485218 |
| 17 | 79406350 |
| 18 | 220536910 |
| 19 | 610487875 |
| 20 | 1684974790 |
| 21 | 4638298536 |
| 22 | 12737460744 |
| 23 | 34902844728 |
| 24 | 95449821672 |
| 25 | 260554112425 |
| 26 | 710056257196 |