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 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 6 |
| 5 | 20 |
| 6 | 50 |
| 7 | 112 |
| 8 | 238 |
| 9 | 492 |
| 10 | 1002 |
| 11 | 2024 |
| 12 | 4070 |
| 13 | 8164 |
| 14 | 16354 |
| 15 | 32736 |
| 16 | 65502 |
| 17 | 131036 |
| 18 | 262106 |
| 19 | 524248 |
| 20 | 1048534 |
| 21 | 2097108 |
| 22 | 4194258 |
| 23 | 8388560 |
| 24 | 16777166 |
| 25 | 33554380 |
| 26 | 67108810 |
| 27 | 134217672 |
| 28 | 268435398 |
| 29 | 536870852 |
| 30 | 1073741762 |