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 | 2 |
| 2 | 9 |
| 3 | 22 |
| 4 | 71 |
| 5 | 186 |
| 6 | 537 |
| 7 | 1434 |
| 8 | 3957 |
| 9 | 10586 |
| 10 | 28603 |
| 11 | 76266 |
| 12 | 203767 |
| 13 | 540986 |
| 14 | 1435533 |
| 15 | 3796050 |
| 16 | 10026015 |
| 17 | 26422350 |
| 18 | 69544765 |
| 19 | 182759750 |
| 20 | 479731113 |
| 21 | 1257750486 |
| 22 | 3294264627 |
| 23 | 8619879726 |
| 24 | 22535782953 |
| 25 | 58869786162 |
| 26 | 153671378139 |
| 27 | 400861115498 |
| 28 | 1045005290059 |
| 29 | 2722601576322 |