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) |
|---|---|
| 1 | 6 |
| 2 | 28 |
| 3 | 110 |
| 4 | 416 |
| 5 | 1558 |
| 6 | 5820 |
| 7 | 21726 |
| 8 | 81088 |
| 9 | 302630 |
| 10 | 1129436 |
| 11 | 4215118 |
| 12 | 15731040 |
| 13 | 58709046 |
| 14 | 219105148 |
| 15 | 817711550 |
| 16 | 3051741056 |
| 17 | 11389252678 |
| 18 | 42505269660 |
| 19 | 158631825966 |
| 20 | 592022034208 |
| 21 | 2209456310870 |
| 22 | 8245803209276 |
| 23 | 30773756526238 |
| 24 | 114849222895680 |
| 25 | 428623135056486 |