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 | 12 |
| 3 | 103 |
| 4 | 1004 |
| 5 | 10005 |
| 6 | 100006 |
| 7 | 1000007 |
| 8 | 10000008 |
| 9 | 100000009 |
| 10 | 1000000010 |
| 11 | 10000000011 |
| 12 | 100000000012 |
| 13 | 1000000000013 |
| 14 | 10000000000014 |
| 15 | 100000000000015 |
| 16 | 1000000000000016 |
| 17 | 10000000000000017 |
| 18 | 100000000000000018 |
| 19 | 1000000000000000019 |
| 20 | 10000000000000000020 |