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 | 1 |
| 2 | 11 |
| 3 | 61 |
| 4 | 311 |
| 5 | 1561 |
| 6 | 7811 |
| 7 | 39061 |
| 8 | 195311 |
| 9 | 976561 |
| 10 | 4882811 |
| 11 | 24414061 |
| 12 | 122070311 |
| 13 | 610351561 |
| 14 | 3051757811 |
| 15 | 15258789061 |
| 16 | 76293945311 |
| 17 | 381469726561 |
| 18 | 1907348632811 |
| 19 | 9536743164061 |
| 20 | 47683715820311 |
| 21 | 238418579101561 |
| 22 | 1192092895507811 |
| 23 | 5960464477539061 |
| 24 | 29802322387695311 |
| 25 | 149011611938476561 |