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 | 1 |
| 1 | 3 |
| 2 | 8 |
| 3 | 19 |
| 4 | 42 |
| 5 | 89 |
| 6 | 184 |
| 7 | 375 |
| 8 | 758 |
| 9 | 1525 |
| 10 | 3060 |
| 11 | 6131 |
| 12 | 12274 |
| 13 | 24561 |
| 14 | 49136 |
| 15 | 98287 |
| 16 | 196590 |
| 17 | 393197 |
| 18 | 786412 |
| 19 | 1572843 |
| 20 | 3145706 |
| 21 | 6291433 |
| 22 | 12582888 |
| 23 | 25165799 |
| 24 | 50331622 |
| 25 | 100663269 |
| 26 | 201326564 |
| 27 | 402653155 |
| 28 | 805306338 |
| 29 | 1610612705 |
| 30 | 3221225440 |