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 | 4 |
| 3 | 17 |
| 4 | 83 |
| 5 | 413 |
| 6 | 2037 |
| 7 | 10010 |
| 8 | 49183 |
| 9 | 241722 |
| 10 | 1188097 |
| 11 | 5839638 |
| 12 | 28702296 |
| 13 | 141073905 |
| 14 | 693388850 |
| 15 | 3408058991 |
| 16 | 16750869834 |
| 17 | 82331801783 |
| 18 | 404667078256 |
| 19 | 1988969518921 |
| 20 | 9775936716973 |
| 21 | 48049473757425 |
| 22 | 236166824233838 |
| 23 | 1160777933797328 |
| 24 | 5705311980035178 |