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 | 5 |
| 4 | 13 |
| 5 | 36 |
| 6 | 104 |
| 7 | 309 |
| 8 | 939 |
| 9 | 2905 |
| 10 | 9118 |
| 11 | 28964 |
| 12 | 92940 |
| 13 | 300808 |
| 14 | 980864 |
| 15 | 3219205 |
| 16 | 10626023 |
| 17 | 35252867 |
| 18 | 117485454 |
| 19 | 393133485 |
| 20 | 1320357501 |
| 21 | 4449298136 |
| 22 | 15038769672 |
| 23 | 50973266380 |
| 24 | 173214422068 |
| 25 | 589998043276 |
| 26 | 2014026871496 |
| 27 | 6889055189032 |
| 28 | 23608722350440 |