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) |
|---|---|
| 3 | 76 |
| 4 | 164 |
| 5 | 340 |
| 6 | 692 |
| 7 | 1396 |
| 8 | 2804 |
| 9 | 5620 |
| 10 | 11252 |
| 11 | 22516 |
| 12 | 45044 |
| 13 | 90100 |
| 14 | 180212 |
| 15 | 360436 |
| 16 | 720884 |
| 17 | 1441780 |
| 18 | 2883572 |
| 19 | 5767156 |
| 20 | 11534324 |
| 21 | 23068660 |
| 22 | 46137332 |
| 23 | 92274676 |
| 24 | 184549364 |
| 25 | 369098740 |
| 26 | 738197492 |
| 27 | 1476394996 |
| 28 | 2952790004 |
| 29 | 5905580020 |