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 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | 5 |
| 6 | 19 |
| 7 | 67 |
| 8 | 236 |
| 9 | 797 |
| 10 | 2678 |
| 11 | 8833 |
| 12 | 28908 |
| 13 | 93569 |
| 14 | 300748 |
| 15 | 959374 |
| 16 | 3042808 |
| 17 | 9597679 |
| 18 | 30134509 |
| 19 | 94218306 |
| 20 | 293509092 |
| 21 | 911325798 |
| 22 | 2821327949 |
| 23 | 8711297753 |
| 24 | 26833501800 |
| 25 | 82476837698 |
| 26 | 253007383067 |
| 27 | 774737986836 |