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 | 4 |
| 2 | 10 |
| 3 | 22 |
| 4 | 54 |
| 5 | 134 |
| 6 | 340 |
| 7 | 872 |
| 8 | 2254 |
| 9 | 5854 |
| 10 | 15250 |
| 11 | 39802 |
| 12 | 104004 |
| 13 | 271964 |
| 14 | 711490 |
| 15 | 1861862 |
| 16 | 4873054 |
| 17 | 12755614 |
| 18 | 33391060 |
| 19 | 87413152 |
| 20 | 228841254 |
| 21 | 599099054 |
| 22 | 1568437210 |
| 23 | 4106182322 |
| 24 | 10750060804 |
| 25 | 28143920884 |
| 26 | 73681573690 |
| 27 | 192900592822 |
| 28 | 505019869254 |
| 29 | 1322158472054 |