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 | 2 |
| 2 | 4 |
| 3 | 9 |
| 4 | 21 |
| 5 | 49 |
| 6 | 114 |
| 7 | 265 |
| 8 | 615 |
| 9 | 1422 |
| 10 | 3272 |
| 11 | 7493 |
| 12 | 17090 |
| 13 | 38850 |
| 14 | 88065 |
| 15 | 199097 |
| 16 | 448953 |
| 17 | 1009788 |
| 18 | 2265642 |
| 19 | 5071611 |
| 20 | 11328395 |
| 21 | 25254093 |
| 22 | 56195143 |
| 23 | 124829822 |
| 24 | 276839061 |
| 25 | 612991848 |
| 26 | 1355268779 |
| 27 | 2992016128 |
| 28 | 6596222234 |
| 29 | 14522634554 |
| 30 | 31933047707 |
| 31 | 70130243427 |