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 | 4 |
| 1 | 9 |
| 2 | 20 |
| 3 | 44 |
| 4 | 97 |
| 5 | 214 |
| 6 | 472 |
| 7 | 1041 |
| 8 | 2296 |
| 9 | 5064 |
| 10 | 11169 |
| 11 | 24634 |
| 12 | 54332 |
| 13 | 119833 |
| 14 | 264300 |
| 15 | 582932 |
| 16 | 1285697 |
| 17 | 2835694 |
| 18 | 6254320 |
| 19 | 13794337 |
| 20 | 30424368 |
| 21 | 67103056 |
| 22 | 148000449 |
| 23 | 326425266 |
| 24 | 719953588 |
| 25 | 1587907625 |
| 26 | 3502240516 |
| 27 | 7724434620 |
| 28 | 17036776865 |
| 29 | 37575794246 |
| 30 | 82876023112 |