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 | 5 |
| 2 | 59 |
| 3 | 509 |
| 4 | 599 |
| 5 | 5009 |
| 6 | 5059 |
| 7 | 5099 |
| 8 | 9059 |
| 9 | 50599 |
| 10 | 50909 |
| 11 | 55009 |
| 12 | 59009 |
| 13 | 59509 |
| 14 | 59999 |
| 15 | 90059 |
| 16 | 90599 |
| 17 | 95009 |
| 18 | 95959 |
| 19 | 99559 |
| 20 | 500009 |
| 21 | 500509 |
| 22 | 500909 |
| 23 | 505559 |
| 24 | 509909 |
| 25 | 509959 |
| 26 | 550009 |
| 27 | 550909 |
| 28 | 559099 |
| 29 | 590099 |
| 30 | 590599 |
| 31 | 590959 |
| 32 | 599009 |
| 33 | 599959 |
| 34 | 599999 |
| 35 | 900959 |