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 | 3 |
| 1 | 7 |
| 2 | 39 |
| 3 | 241 |
| 4 | 1499 |
| 5 | 9327 |
| 6 | 58035 |
| 7 | 361109 |
| 8 | 2246915 |
| 9 | 13980895 |
| 10 | 86992799 |
| 11 | 541292033 |
| 12 | 3368061131 |
| 13 | 20956960551 |
| 14 | 130399710235 |
| 15 | 811381230021 |
| 16 | 5048627019523 |
| 17 | 31413882696791 |
| 18 | 195465425009943 |
| 19 | 1216237188605169 |
| 20 | 7567747077883259 |