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 | 9 |
| 1 | 19 |
| 2 | 40 |
| 3 | 84 |
| 4 | 176 |
| 5 | 368 |
| 6 | 768 |
| 7 | 1600 |
| 8 | 3328 |
| 9 | 6912 |
| 10 | 14336 |
| 11 | 29696 |
| 12 | 61440 |
| 13 | 126976 |
| 14 | 262144 |
| 15 | 540672 |
| 16 | 1114112 |
| 17 | 2293760 |
| 18 | 4718592 |
| 19 | 9699328 |
| 20 | 19922944 |
| 21 | 40894464 |
| 22 | 83886080 |
| 23 | 171966464 |
| 24 | 352321536 |
| 25 | 721420288 |
| 26 | 1476395008 |
| 27 | 3019898880 |