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 | 0 |
| 2 | 0 |
| 3 | 2 |
| 4 | 8 |
| 5 | 22 |
| 6 | 52 |
| 7 | 114 |
| 8 | 240 |
| 9 | 494 |
| 10 | 1004 |
| 11 | 2026 |
| 12 | 4072 |
| 13 | 8166 |
| 14 | 16356 |
| 15 | 32738 |
| 16 | 65504 |
| 17 | 131038 |
| 18 | 262108 |
| 19 | 524250 |
| 20 | 1048536 |
| 21 | 2097110 |
| 22 | 4194260 |
| 23 | 8388562 |
| 24 | 16777168 |
| 25 | 33554382 |
| 26 | 67108812 |
| 27 | 134217674 |
| 28 | 268435400 |
| 29 | 536870854 |
| 30 | 1073741764 |
| 31 | 2147483586 |