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 | 33 |
| 3 | 127 |
| 4 | 700 |
| 5 | 3175 |
| 6 | 15541 |
| 7 | 74736 |
| 8 | 358341 |
| 9 | 1729617 |
| 10 | 8308924 |
| 11 | 40006463 |
| 12 | 192481249 |
| 13 | 926168176 |
| 14 | 4456879585 |
| 15 | 21445119255 |
| 16 | 103193473908 |
| 17 | 496552428929 |
| 18 | 2389355832929 |
| 19 | 11497320733428 |
| 20 | 55323763675221 |
| 21 | 266211857683333 |