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 | 17 |
| 2 | 51 |
| 3 | 161 |
| 4 | 531 |
| 5 | 1817 |
| 6 | 6411 |
| 7 | 23201 |
| 8 | 85731 |
| 9 | 322217 |
| 10 | 1227771 |
| 11 | 4729841 |
| 12 | 18379731 |
| 13 | 71908217 |
| 14 | 282817131 |
| 15 | 1116854081 |
| 16 | 4424238531 |
| 17 | 17567551817 |
| 18 | 69882262491 |
| 19 | 278365739921 |
| 20 | 1109974078131 |
| 21 | 4429431765017 |
| 22 | 17686337611851 |
| 23 | 70651190491361 |
| 24 | 282322298874531 |