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 | 2 |
| 3 | 6 |
| 4 | 15 |
| 5 | 44 |
| 6 | 128 |
| 7 | 386 |
| 8 | 1179 |
| 9 | 3679 |
| 10 | 11601 |
| 11 | 37030 |
| 12 | 119262 |
| 13 | 387325 |
| 14 | 1266647 |
| 15 | 4168264 |
| 16 | 13791565 |
| 17 | 45856091 |
| 18 | 153134306 |
| 19 | 513403575 |
| 20 | 1727395042 |
| 21 | 5830866601 |
| 22 | 19740613869 |
| 23 | 67014421326 |
| 24 | 228066659185 |
| 25 | 777961702283 |
| 26 | 2659398743509 |
| 27 | 9109015516017 |
| 28 | 31258117755635 |