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 | 2 |
| 3 | 4 |
| 4 | 10 |
| 5 | 20 |
| 6 | 44 |
| 7 | 88 |
| 8 | 182 |
| 9 | 364 |
| 10 | 740 |
| 11 | 1480 |
| 12 | 2980 |
| 13 | 5960 |
| 14 | 11960 |
| 15 | 23920 |
| 16 | 47914 |
| 17 | 95828 |
| 18 | 191804 |
| 19 | 383608 |
| 20 | 767500 |
| 21 | 1535000 |
| 22 | 3070568 |
| 23 | 6141136 |
| 24 | 12283388 |
| 25 | 24566776 |
| 26 | 49135784 |
| 27 | 98271568 |
| 28 | 196547560 |
| 29 | 393095120 |
| 30 | 786199088 |
| 31 | 1572398176 |
| 32 | 3144813974 |