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 | 6 |
| 2 | 28 |
| 3 | 66 |
| 4 | 666 |
| 5 | 2628 |
| 6 | 228826 |
| 7 | 828828 |
| 8 | 2222886 |
| 9 | 66268828 |
| 10 | 222868828 |
| 11 | 286262628 |
| 12 | 628262628 |
| 13 | 688668828 |
| 14 | 862266628 |
| 15 | 2266226826 |
| 16 | 622686668286628 |
| 17 | 866688628826628 |
| 18 | 68262228626828682628 |
| 19 | 288626826822666288666 |
| 20 | 66288228282628868868828 |
| 21 | 28622882886686262262866288686266 |