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 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 1 |
| 5 | 3 |
| 6 | 7 |
| 7 | 16 |
| 8 | 40 |
| 9 | 98 |
| 10 | 246 |
| 11 | 624 |
| 12 | 1596 |
| 13 | 4120 |
| 14 | 10708 |
| 15 | 28009 |
| 16 | 73673 |
| 17 | 194743 |
| 18 | 517067 |
| 19 | 1378365 |
| 20 | 3687665 |
| 21 | 9898417 |
| 22 | 26649117 |
| 23 | 71943947 |
| 24 | 194717215 |
| 25 | 528236599 |
| 26 | 1436122339 |
| 27 | 3912244667 |
| 28 | 10677558423 |
| 29 | 29192753795 |
| 30 | 79944089343 |
| 31 | 219261036592 |
| 32 | 602226736360 |