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 | 1 |
| 3 | 4 |
| 4 | 12 |
| 5 | 30 |
| 6 | 69 |
| 7 | 150 |
| 8 | 316 |
| 9 | 652 |
| 10 | 1329 |
| 11 | 2688 |
| 12 | 5412 |
| 13 | 10866 |
| 14 | 21781 |
| 15 | 43618 |
| 16 | 87300 |
| 17 | 174672 |
| 18 | 349425 |
| 19 | 698940 |
| 20 | 1397980 |
| 21 | 2796070 |
| 22 | 5592261 |
| 23 | 11184654 |
| 24 | 22369452 |
| 25 | 44739060 |
| 26 | 89478289 |
| 27 | 178956760 |
| 28 | 357913716 |
| 29 | 715827642 |
| 30 | 1431655509 |
| 31 | 2863311258 |
| 32 | 5726622772 |