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 | 4 |
| 6 | 11 |
| 7 | 30 |
| 8 | 78 |
| 9 | 205 |
| 10 | 546 |
| 11 | 1455 |
| 12 | 4062 |
| 13 | 11192 |
| 14 | 31889 |
| 15 | 88487 |
| 16 | 254594 |
| 17 | 710683 |
| 18 | 2047705 |
| 19 | 5711439 |
| 20 | 16455169 |
| 21 | 45894868 |
| 22 | 132118562 |
| 23 | 368149344 |
| 24 | 1059171430 |
| 25 | 2950384277 |
| 26 | 8484556353 |