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 | 1 |
| 2 | 3 |
| 3 | 11 |
| 4 | 65 |
| 5 | 573 |
| 6 | 6547 |
| 7 | 89639 |
| 8 | 1414417 |
| 9 | 25148617 |
| 10 | 496416579 |
| 11 | 10762275539 |
| 12 | 254153371121 |
| 13 | 6494217863461 |
| 14 | 178558132802259 |
| 15 | 5257524611172751 |
| 16 | 165089697983580641 |
| 17 | 5507950426778674129 |
| 18 | 194605351254360182403 |
| 19 | 7259714571747394749147 |
| 20 | 285174902634083710549601 |