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 | 10 |
| 3 | 30 |
| 4 | 74 |
| 5 | 166 |
| 6 | 354 |
| 7 | 734 |
| 8 | 1498 |
| 9 | 3030 |
| 10 | 6098 |
| 11 | 12238 |
| 12 | 24522 |
| 13 | 49094 |
| 14 | 98242 |
| 15 | 196542 |
| 16 | 393146 |
| 17 | 786358 |
| 18 | 1572786 |
| 19 | 3145646 |
| 20 | 6291370 |
| 21 | 12582822 |
| 22 | 25165730 |
| 23 | 50331550 |
| 24 | 100663194 |
| 25 | 201326486 |
| 26 | 402653074 |
| 27 | 805306254 |
| 28 | 1610612618 |
| 29 | 3221225350 |
| 30 | 6442450818 |
| 31 | 12884901758 |
| 32 | 25769803642 |