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 | 0 |
| 2 | 4 |
| 3 | 17 |
| 4 | 46 |
| 5 | 116 |
| 6 | 288 |
| 7 | 683 |
| 8 | 1548 |
| 9 | 3403 |
| 10 | 7320 |
| 11 | 15461 |
| 12 | 32146 |
| 13 | 65954 |
| 14 | 133800 |
| 15 | 268804 |
| 16 | 535434 |
| 17 | 1058533 |
| 18 | 2078732 |
| 19 | 4057858 |
| 20 | 7878814 |
| 21 | 15223495 |
| 22 | 29285368 |
| 23 | 56109673 |
| 24 | 107108104 |
| 25 | 203766859 |
| 26 | 386443052 |
| 27 | 730768044 |
| 28 | 1378180568 |
| 29 | 2592664120 |
| 30 | 4866008208 |
| 31 | 9112796113 |