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 | 2 |
| 2 | 6 |
| 3 | 15 |
| 4 | 33 |
| 5 | 69 |
| 6 | 140 |
| 7 | 280 |
| 8 | 556 |
| 9 | 1101 |
| 10 | 2179 |
| 11 | 4315 |
| 12 | 8554 |
| 13 | 16978 |
| 14 | 33738 |
| 15 | 67115 |
| 16 | 133637 |
| 17 | 266305 |
| 18 | 531032 |
| 19 | 1059500 |
| 20 | 2114840 |
| 21 | 4222937 |
| 22 | 8434951 |
| 23 | 16852215 |
| 24 | 33675798 |
| 25 | 67305254 |
| 26 | 134535510 |
| 27 | 268949655 |
| 28 | 537702921 |
| 29 | 1075088061 |
| 30 | 2149661924 |