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) |
|---|---|
| 2 | 1 |
| 3 | 13 |
| 4 | 80 |
| 5 | 549 |
| 6 | 3851 |
| 7 | 26499 |
| 8 | 183521 |
| 9 | 1269684 |
| 10 | 8782833 |
| 11 | 60764640 |
| 12 | 420375910 |
| 13 | 2908245096 |
| 14 | 20119820809 |
| 15 | 139192751951 |
| 16 | 962962619849 |
| 17 | 6661962019139 |
| 18 | 46088745527485 |
| 19 | 318850883829314 |
| 20 | 2205872265781839 |
| 21 | 15260652269262421 |
| 22 | 105576152878533354 |
| 23 | 730396306808551777 |
| 24 | 5053023343572544589 |