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 | 0 |
| 1 | 0 |
| 2 | 1 |
| 3 | 1 |
| 4 | 4 |
| 5 | 8 |
| 6 | 25 |
| 7 | 53 |
| 8 | 164 |
| 9 | 348 |
| 10 | 1077 |
| 11 | 2285 |
| 12 | 7072 |
| 13 | 15004 |
| 14 | 46437 |
| 15 | 98521 |
| 16 | 304920 |
| 17 | 646920 |
| 18 | 2002201 |
| 19 | 4247881 |
| 20 | 13147084 |
| 21 | 27892928 |
| 22 | 86327905 |
| 23 | 183153773 |
| 24 | 566856284 |
| 25 | 1202645508 |
| 26 | 3722157357 |
| 27 | 7896950165 |
| 28 | 24440860552 |
| 29 | 51853868404 |
| 30 | 160486408077 |