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 | 1 |
| 2 | 1 |
| 3 | 4 |
| 4 | 8 |
| 5 | 23 |
| 6 | 55 |
| 7 | 144 |
| 8 | 360 |
| 9 | 921 |
| 10 | 2329 |
| 11 | 5924 |
| 12 | 15024 |
| 13 | 38159 |
| 14 | 96847 |
| 15 | 245888 |
| 16 | 624176 |
| 17 | 1584593 |
| 18 | 4022609 |
| 19 | 10211940 |
| 20 | 25924088 |
| 21 | 65811431 |
| 22 | 167069767 |
| 23 | 424126160 |
| 24 | 1076693080 |
| 25 | 2733310377 |
| 26 | 6938824361 |
| 27 | 17615009476 |
| 28 | 44717740000 |
| 29 | 113521160607 |
| 30 | 288186606623 |