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 | 3 |
| 1 | 4 |
| 2 | 9 |
| 3 | 19 |
| 4 | 40 |
| 5 | 92 |
| 6 | 220 |
| 7 | 513 |
| 8 | 1142 |
| 9 | 2436 |
| 10 | 5031 |
| 11 | 10164 |
| 12 | 20272 |
| 13 | 40258 |
| 14 | 80230 |
| 15 | 161458 |
| 16 | 329211 |
| 17 | 679921 |
| 18 | 1417373 |
| 19 | 2966192 |
| 20 | 6195952 |
| 21 | 12855389 |
| 22 | 26402016 |
| 23 | 53574712 |
| 24 | 107369761 |
| 25 | 212694661 |
| 26 | 417192840 |
| 27 | 812167806 |
| 28 | 1573409607 |
| 29 | 3041468738 |