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 | 10 |
| 3 | 34 |
| 4 | 118 |
| 5 | 417 |
| 6 | 1497 |
| 7 | 5448 |
| 8 | 20063 |
| 9 | 74649 |
| 10 | 280252 |
| 11 | 1060439 |
| 12 | 4040413 |
| 13 | 15488981 |
| 14 | 59701236 |
| 15 | 231236830 |
| 16 | 899559100 |
| 17 | 3513314664 |
| 18 | 13770811198 |
| 19 | 54152480421 |
| 20 | 213585706927 |
| 21 | 844723104691 |
| 22 | 3349274471386 |
| 23 | 13310603555085 |
| 24 | 53012829376985 |
| 25 | 211560158583657 |
| 26 | 845856494229348 |
| 27 | 3387782725245302 |
| 28 | 13590698721293800 |
| 29 | 54604853170818121 |
| 30 | 219706932640295523 |