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 | 4 |
| 2 | 4 |
| 3 | 13 |
| 4 | 49 |
| 5 | 85 |
| 6 | 202 |
| 7 | 643 |
| 8 | 1408 |
| 9 | 3226 |
| 10 | 9013 |
| 11 | 21685 |
| 12 | 50719 |
| 13 | 131836 |
| 14 | 327001 |
| 15 | 783472 |
| 16 | 1969996 |
| 17 | 4913005 |
| 18 | 11964253 |
| 19 | 29694217 |
| 20 | 73911262 |
| 21 | 181589539 |
| 22 | 448837492 |
| 23 | 1114038850 |
| 24 | 2748344701 |
| 25 | 6787882129 |
| 26 | 16814231779 |
| 27 | 41549334088 |
| 28 | 102640273249 |