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 | 12 |
| 3 | 28 |
| 4 | 64 |
| 5 | 148 |
| 6 | 340 |
| 7 | 780 |
| 8 | 1792 |
| 9 | 4116 |
| 10 | 9452 |
| 11 | 21708 |
| 12 | 49856 |
| 13 | 114500 |
| 14 | 262964 |
| 15 | 603932 |
| 16 | 1387008 |
| 17 | 3185444 |
| 18 | 7315788 |
| 19 | 16801660 |
| 20 | 38587200 |
| 21 | 88620532 |
| 22 | 203528596 |
| 23 | 467429932 |
| 24 | 1073513728 |
| 25 | 2465464116 |
| 26 | 5662259500 |
| 27 | 13004116524 |
| 28 | 29865647552 |
| 29 | 68590349988 |
| 30 | 157526673524 |