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 | 11 |
| 2 | 51 |
| 3 | 211 |
| 4 | 851 |
| 5 | 3411 |
| 6 | 13651 |
| 7 | 54611 |
| 8 | 218451 |
| 9 | 873811 |
| 10 | 3495251 |
| 11 | 13981011 |
| 12 | 55924051 |
| 13 | 223696211 |
| 14 | 894784851 |
| 15 | 3579139411 |
| 16 | 14316557651 |
| 17 | 57266230611 |
| 18 | 229064922451 |
| 19 | 916259689811 |
| 20 | 3665038759251 |
| 21 | 14660155037011 |
| 22 | 58640620148051 |
| 23 | 234562480592211 |
| 24 | 938249922368851 |