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 | 8 |
| 5 | 24 |
| 6 | 73 |
| 7 | 183 |
| 8 | 470 |
| 9 | 1112 |
| 10 | 2592 |
| 11 | 5876 |
| 12 | 13233 |
| 13 | 29316 |
| 14 | 64329 |
| 15 | 140028 |
| 16 | 302824 |
| 17 | 651101 |
| 18 | 1393204 |
| 19 | 2968129 |
| 20 | 6300084 |
| 21 | 13326815 |
| 22 | 28108564 |
| 23 | 59123162 |
| 24 | 124065274 |
| 25 | 259759346 |
| 26 | 542781169 |
| 27 | 1132075405 |
| 28 | 2357197804 |
| 29 | 4900443545 |
| 30 | 10173068455 |
| 31 | 21090365684 |