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) |
|---|---|
| 1 | 1 |
| 2 | 81 |
| 3 | 11881 |
| 4 | 811801 |
| 5 | 1018081 |
| 6 | 81018001 |
| 7 | 100180081 |
| 8 | 108180801 |
| 9 | 8100180001 |
| 10 | 10001800081 |
| 11 | 10181011801 |
| 12 | 810001800001 |
| 13 | 1000018000081 |
| 14 | 1008018008001 |
| 15 | 80181118180881 |
| 16 | 81000018000001 |
| 17 | 100000180000081 |
| 18 | 100180101018001 |
| 19 | 1180000888001881 |
| 20 | 8100000180000001 |
| 21 | 10000001800000081 |