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 | 7 |
| 2 | 38 |
| 3 | 196 |
| 4 | 1001 |
| 5 | 5110 |
| 6 | 26093 |
| 7 | 133252 |
| 8 | 680510 |
| 9 | 3475339 |
| 10 | 17748434 |
| 11 | 90640627 |
| 12 | 462898478 |
| 13 | 2364006148 |
| 14 | 12072895733 |
| 15 | 61655851222 |
| 16 | 314874250049 |
| 17 | 1608051650884 |
| 18 | 8212262868470 |
| 19 | 41939735818687 |
| 20 | 214184746483778 |
| 21 | 1093833919809295 |
| 22 | 5586171115205846 |
| 23 | 28528378178106436 |
| 24 | 145693417671662033 |
| 25 | 744051127629095062 |
| 26 | 3799842775146922277 |
| 27 | 19405662567631938052 |
| 28 | 99104031922539424718 |