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 | 0 |
| 1 | 5 |
| 2 | 51 |
| 3 | 498 |
| 4 | 5004 |
| 5 | 50028 |
| 6 | 500014 |
| 7 | 4999954 |
| 8 | 49999325 |
| 9 | 499998777 |
| 10 | 5000002329 |
| 11 | 49999998413 |
| 12 | 499999949299 |
| 13 | 4999999991841 |
| 14 | 49999999683763 |
| 15 | 499999999022579 |
| 16 | 5000000005362272 |
| 17 | 50000000022520652 |
| 18 | 500000000055534895 |
| 19 | 5000000000274296550 |
| 20 | 50000000000909149240 |