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 | 1 |
| 2 | 3 |
| 3 | 5 |
| 4 | 15 |
| 5 | 33 |
| 6 | 91 |
| 7 | 221 |
| 8 | 583 |
| 9 | 1465 |
| 10 | 3795 |
| 11 | 9653 |
| 12 | 24831 |
| 13 | 63441 |
| 14 | 162763 |
| 15 | 416525 |
| 16 | 1067575 |
| 17 | 2733673 |
| 18 | 7003971 |
| 19 | 17938661 |
| 20 | 45954543 |
| 21 | 117709185 |
| 22 | 301527355 |
| 23 | 772364093 |
| 24 | 1978473511 |