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 | 3 |
| 2 | 9 |
| 3 | 24 |
| 4 | 70 |
| 5 | 200 |
| 6 | 576 |
| 7 | 1662 |
| 8 | 4793 |
| 9 | 13824 |
| 10 | 39876 |
| 11 | 115021 |
| 12 | 331776 |
| 13 | 957008 |
| 14 | 2760488 |
| 15 | 7962624 |
| 16 | 22968183 |
| 17 | 66251702 |
| 18 | 191102976 |
| 19 | 551236371 |
| 20 | 1590040836 |
| 21 | 4586471424 |
| 22 | 13229672881 |
| 23 | 38160980056 |
| 24 | 110075314176 |
| 25 | 317512149144 |
| 26 | 915863521340 |
| 27 | 2641807540224 |
| 28 | 7620291579446 |