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 | 0 |
| 1 | 2 |
| 2 | 4 |
| 3 | 9 |
| 4 | 22 |
| 5 | 53 |
| 6 | 129 |
| 7 | 327 |
| 8 | 847 |
| 9 | 2227 |
| 10 | 5968 |
| 11 | 16097 |
| 12 | 43934 |
| 13 | 120739 |
| 14 | 334349 |
| 15 | 931260 |
| 16 | 2607165 |
| 17 | 7332159 |
| 18 | 20700806 |
| 19 | 58648288 |
| 20 | 166677978 |
| 21 | 475023803 |
| 22 | 1357200840 |
| 23 | 3886548158 |
| 24 | 11152818693 |
| 25 | 32064929886 |
| 26 | 92349038518 |
| 27 | 266398236486 |
| 28 | 769616513836 |
| 29 | 2226457080707 |
| 30 | 6449247674296 |
| 31 | 18703411700669 |
| 32 | 54301968156067 |
| 33 | 157820174545456 |