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 | 20 |
| 2 | 120 |
| 3 | 1030 |
| 4 | 10040 |
| 5 | 100050 |
| 6 | 1000060 |
| 7 | 10000070 |
| 8 | 100000080 |
| 9 | 1000000090 |
| 10 | 10000000100 |
| 11 | 100000000110 |
| 12 | 1000000000120 |
| 13 | 10000000000130 |
| 14 | 100000000000140 |
| 15 | 1000000000000150 |
| 16 | 10000000000000160 |
| 17 | 100000000000000170 |
| 18 | 1000000000000000180 |
| 19 | 10000000000000000190 |
| 20 | 100000000000000000200 |