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 | 40 |
| 4 | 82 |
| 5 | 328 |
| 6 | 820 |
| 7 | 3280 |
| 8 | 6562 |
| 9 | 26248 |
| 10 | 65620 |
| 11 | 262480 |
| 12 | 538084 |
| 13 | 2152336 |
| 14 | 5380840 |
| 15 | 21523360 |
| 16 | 43046722 |
| 17 | 172186888 |
| 18 | 430467220 |
| 19 | 1721868880 |
| 20 | 3529831204 |
| 21 | 14119324816 |
| 22 | 35298312040 |
| 23 | 141193248160 |
| 24 | 282472589764 |
| 25 | 1129890359056 |