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 | 2 |
| 2 | 4 |
| 3 | 8 |
| 4 | 16 |
| 5 | 34 |
| 6 | 76 |
| 7 | 176 |
| 8 | 416 |
| 9 | 994 |
| 10 | 2388 |
| 11 | 5752 |
| 12 | 13872 |
| 13 | 33474 |
| 14 | 80796 |
| 15 | 195040 |
| 16 | 470848 |
| 17 | 1136706 |
| 18 | 2744228 |
| 19 | 6625128 |
| 20 | 15994448 |
| 21 | 38613986 |
| 22 | 93222380 |
| 23 | 225058704 |
| 24 | 543339744 |
| 25 | 1311738146 |
| 26 | 3166815988 |
| 27 | 7645370072 |
| 28 | 18457556080 |
| 29 | 44560482178 |
| 30 | 107578520380 |
| 31 | 259717522880 |