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) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 6 |
| 4 | 9 |
| 5 | 61 |
| 6 | 121 |
| 7 | 544 |
| 8 | 1357 |
| 9 | 5100 |
| 10 | 14340 |
| 11 | 49324 |
| 12 | 147230 |
| 13 | 485141 |
| 14 | 1491460 |
| 15 | 4812843 |
| 16 | 15012153 |
| 17 | 47950974 |
| 18 | 150636184 |
| 19 | 478755674 |
| 20 | 1509249756 |
| 21 | 4785018013 |
| 22 | 15110309428 |
| 23 | 47849311565 |
| 24 | 151226992088 |
| 25 | 478604645313 |
| 26 | 1513243349293 |
| 27 | 4787751445331 |