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 | 0 |
| 1 | 3 |
| 2 | 14 |
| 3 | 54 |
| 4 | 188 |
| 5 | 615 |
| 6 | 1932 |
| 7 | 5901 |
| 8 | 17656 |
| 9 | 52002 |
| 10 | 151270 |
| 11 | 435633 |
| 12 | 1244184 |
| 13 | 3528759 |
| 14 | 9949058 |
| 15 | 27907470 |
| 16 | 77933552 |
| 17 | 216784731 |
| 18 | 600935076 |
| 19 | 1660672257 |
| 20 | 4576522540 |
| 21 | 12580566138 |
| 22 | 34504747354 |
| 23 | 94440719589 |
| 24 | 257998970928 |
| 25 | 703593828075 |
| 26 | 1915713858422 |
| 27 | 5208304147686 |