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 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 15 |
| 5 | 39 |
| 6 | 108 |
| 7 | 290 |
| 8 | 781 |
| 9 | 2050 |
| 10 | 5434 |
| 11 | 14210 |
| 12 | 37150 |
| 13 | 96347 |
| 14 | 248250 |
| 15 | 636278 |
| 16 | 1620721 |
| 17 | 4108340 |
| 18 | 10361338 |
| 19 | 26016060 |
| 20 | 65019655 |
| 21 | 161831393 |
| 22 | 401090324 |
| 23 | 990229108 |
| 24 | 2435316984 |
| 25 | 5967684036 |
| 26 | 14572351628 |
| 27 | 35464928382 |
| 28 | 86033632280 |
| 29 | 208062026930 |
| 30 | 501676936146 |