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 | 7 |
| 3 | 28 |
| 4 | 116 |
| 5 | 480 |
| 6 | 1968 |
| 7 | 8000 |
| 8 | 32320 |
| 9 | 130048 |
| 10 | 521984 |
| 11 | 2092032 |
| 12 | 8377344 |
| 13 | 33529856 |
| 14 | 134164480 |
| 15 | 536756224 |
| 16 | 2147237888 |
| 17 | 8589410304 |
| 18 | 34358624256 |
| 19 | 137436594176 |
| 20 | 549750833152 |
| 21 | 2199012769792 |
| 22 | 8796071002112 |
| 23 | 35184325951488 |
| 24 | 140737391886336 |
| 25 | 562949752094720 |