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 | 5 |
| 2 | 20 |
| 3 | 95 |
| 4 | 400 |
| 5 | 1561 |
| 6 | 5915 |
| 7 | 21610 |
| 8 | 76585 |
| 9 | 265075 |
| 10 | 898622 |
| 11 | 2992235 |
| 12 | 9810290 |
| 13 | 31727815 |
| 14 | 101379175 |
| 15 | 320464280 |
| 16 | 1003259080 |
| 17 | 3113576320 |
| 18 | 9586763720 |
| 19 | 29305985800 |
| 20 | 88997753446 |
| 21 | 268642069750 |
| 22 | 806394498200 |
| 23 | 2408144329250 |
| 24 | 7157177344225 |
| 25 | 21177323087891 |