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 | 2 |
| 2 | 6 |
| 3 | 20 |
| 4 | 13 |
| 5 | 179 |
| 6 | 546 |
| 7 | 762 |
| 8 | 1816 |
| 9 | 14750 |
| 10 | 41855 |
| 11 | 130334 |
| 12 | 184744 |
| 13 | 854072 |
| 14 | 3087888 |
| 15 | 10703601 |
| 16 | 15578299 |
| 17 | 96694224 |
| 18 | 108119693 |
| 19 | 514354272 |
| 20 | 1569052954 |
| 21 | 7807991046 |
| 22 | 23534408763 |
| 23 | 39516990609 |
| 24 | 76222439041 |
| 25 | 402903897267 |
| 26 | 1860094976924 |
| 27 | 5552186457189 |
| 28 | 6550591089598 |