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 | 7 |
| 2 | 46 |
| 3 | 290 |
| 4 | 1775 |
| 5 | 10625 |
| 6 | 62500 |
| 7 | 362500 |
| 8 | 2078125 |
| 9 | 11796875 |
| 10 | 66406250 |
| 11 | 371093750 |
| 12 | 2060546875 |
| 13 | 11376953125 |
| 14 | 62500000000 |
| 15 | 341796875000 |
| 16 | 1861572265625 |
| 17 | 10101318359375 |
| 18 | 54626464843750 |
| 19 | 294494628906250 |
| 20 | 1583099365234375 |