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 | 1 |
| 4 | 0 |
| 5 | 1 |
| 6 | 2 |
| 7 | 4 |
| 8 | 7 |
| 9 | 15 |
| 10 | 28 |
| 11 | 56 |
| 12 | 110 |
| 13 | 220 |
| 14 | 436 |
| 15 | 878 |
| 16 | 1762 |
| 17 | 3560 |
| 18 | 7205 |
| 19 | 14650 |
| 20 | 29838 |
| 21 | 60991 |
| 22 | 124938 |
| 23 | 256628 |
| 24 | 528238 |
| 25 | 1089834 |
| 26 | 2252860 |
| 27 | 4666304 |
| 28 | 9682422 |
| 29 | 20125777 |
| 30 | 41900433 |
| 31 | 87369029 |
| 32 | 182441944 |
| 33 | 381499040 |
| 34 | 798782945 |
| 35 | 1674575394 |
| 36 | 3514733683 |
| 37 | 7385298837 |
| 38 | 15534856067 |