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 | 0 |
| 1 | 2 |
| 2 | 10 |
| 3 | 44 |
| 4 | 186 |
| 5 | 772 |
| 6 | 3172 |
| 7 | 12952 |
| 8 | 52666 |
| 9 | 213524 |
| 10 | 863820 |
| 11 | 3488872 |
| 12 | 14073060 |
| 13 | 56708264 |
| 14 | 228318856 |
| 15 | 918624304 |
| 16 | 3693886906 |
| 17 | 14846262964 |
| 18 | 59644341436 |
| 19 | 239532643144 |
| 20 | 961665098956 |
| 21 | 3859788636664 |
| 22 | 15488087080696 |
| 23 | 62135313450064 |