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 | 10 |
| 2 | 30 |
| 3 | 100 |
| 4 | 354 |
| 5 | 1300 |
| 6 | 4890 |
| 7 | 18700 |
| 8 | 72354 |
| 9 | 282340 |
| 10 | 1108650 |
| 11 | 4373500 |
| 12 | 17312754 |
| 13 | 68711380 |
| 14 | 273234810 |
| 15 | 1088123500 |
| 16 | 4338079554 |
| 17 | 17309140420 |
| 18 | 69107159370 |
| 19 | 276040692700 |
| 20 | 1102999460754 |
| 21 | 4408508961460 |
| 22 | 17623571298330 |
| 23 | 70462895745100 |
| 24 | 281757423024354 |