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) |
|---|---|
| 2 | 0 |
| 3 | 3 |
| 4 | 10 |
| 5 | 25 |
| 6 | 56 |
| 7 | 119 |
| 8 | 246 |
| 9 | 501 |
| 10 | 1012 |
| 11 | 2035 |
| 12 | 4082 |
| 13 | 8177 |
| 14 | 16368 |
| 15 | 32751 |
| 16 | 65518 |
| 17 | 131053 |
| 18 | 262124 |
| 19 | 524267 |
| 20 | 1048554 |
| 21 | 2097129 |
| 22 | 4194280 |
| 23 | 8388583 |
| 24 | 16777190 |
| 25 | 33554405 |
| 26 | 67108836 |
| 27 | 134217699 |
| 28 | 268435426 |
| 29 | 536870881 |
| 30 | 1073741792 |
| 31 | 2147483615 |