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 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 10 |
| 5 | 25 |
| 6 | 65 |
| 7 | 169 |
| 8 | 442 |
| 9 | 1156 |
| 10 | 3026 |
| 11 | 7921 |
| 12 | 20737 |
| 13 | 54289 |
| 14 | 142130 |
| 15 | 372100 |
| 16 | 974170 |
| 17 | 2550409 |
| 18 | 6677057 |
| 19 | 17480761 |
| 20 | 45765226 |
| 21 | 119814916 |
| 22 | 313679522 |
| 23 | 821223649 |
| 24 | 2149991425 |
| 25 | 5628750625 |
| 26 | 14736260450 |
| 27 | 38580030724 |
| 28 | 101003831722 |