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 | 1 |
| 3 | 1 |
| 4 | 7 |
| 5 | 25 |
| 6 | 61 |
| 7 | 121 |
| 8 | 283 |
| 9 | 841 |
| 10 | 2521 |
| 11 | 6769 |
| 12 | 17119 |
| 13 | 44665 |
| 14 | 123685 |
| 15 | 347497 |
| 16 | 954787 |
| 17 | 2578297 |
| 18 | 7001617 |
| 19 | 19307089 |
| 20 | 53601175 |
| 21 | 148305817 |
| 22 | 408681997 |
| 23 | 1127558041 |
| 24 | 3124344427 |
| 25 | 8681565865 |
| 26 | 24127128841 |
| 27 | 67020060721 |
| 28 | 186282015823 |