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 | 1 |
| 2 | 4 |
| 3 | 13 |
| 4 | 38 |
| 5 | 105 |
| 6 | 280 |
| 7 | 729 |
| 8 | 1866 |
| 9 | 4717 |
| 10 | 11812 |
| 11 | 29365 |
| 12 | 72590 |
| 13 | 178641 |
| 14 | 438064 |
| 15 | 1071153 |
| 16 | 2613138 |
| 17 | 6362965 |
| 18 | 15470140 |
| 19 | 37565389 |
| 20 | 91125206 |
| 21 | 220864377 |
| 22 | 534951112 |
| 23 | 1294960905 |
| 24 | 3133261530 |
| 25 | 7578261181 |
| 26 | 18323338324 |
| 27 | 44292046693 |
| 28 | 107041649438 |