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 | 7 |
| 2 | 53 |
| 3 | 509 |
| 4 | 5081 |
| 5 | 50123 |
| 6 | 500057 |
| 7 | 5000087 |
| 8 | 50000243 |
| 9 | 500000069 |
| 10 | 5000000063 |
| 11 | 50000000189 |
| 12 | 500000000231 |
| 13 | 5000000001569 |
| 14 | 50000000000381 |
| 15 | 500000000000231 |
| 16 | 5000000000001443 |
| 17 | 50000000000001113 |
| 18 | 500000000000000321 |
| 19 | 5000000000000000339 |
| 20 | 50000000000000001353 |
| 21 | 500000000000000000363 |