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 | 1 |
| 4 | 4 |
| 5 | 13 |
| 6 | 35 |
| 7 | 89 |
| 8 | 221 |
| 9 | 499 |
| 10 | 1146 |
| 11 | 2755 |
| 12 | 6750 |
| 13 | 16570 |
| 14 | 40293 |
| 15 | 97355 |
| 16 | 234629 |
| 17 | 565632 |
| 18 | 1365768 |
| 19 | 3303221 |
| 20 | 7992751 |
| 21 | 19333657 |
| 22 | 46743931 |
| 23 | 112983171 |
| 24 | 273083004 |
| 25 | 660115058 |
| 26 | 1595837810 |
| 27 | 3858133501 |
| 28 | 9327445000 |
| 29 | 22549449187 |
| 30 | 54512990509 |
| 31 | 131783650621 |