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 | 20 |
| 5 | 46 |
| 6 | 109 |
| 7 | 262 |
| 8 | 638 |
| 9 | 1569 |
| 10 | 3886 |
| 11 | 9680 |
| 12 | 24225 |
| 13 | 60856 |
| 14 | 153368 |
| 15 | 387573 |
| 16 | 981742 |
| 17 | 2491934 |
| 18 | 6336721 |
| 19 | 16139616 |
| 20 | 41166912 |
| 21 | 105139773 |
| 22 | 268841100 |
| 23 | 688157430 |
| 24 | 1763206441 |
| 25 | 4521749642 |
| 26 | 11605580290 |
| 27 | 29809644693 |
| 28 | 76621733444 |
| 29 | 197074591420 |
| 30 | 507193044993 |