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 | 7 |
| 2 | 49 |
| 3 | 336 |
| 4 | 2289 |
| 5 | 15477 |
| 6 | 104006 |
| 7 | 695135 |
| 8 | 4623815 |
| 9 | 30625210 |
| 10 | 202067047 |
| 11 | 1328649469 |
| 12 | 8708852838 |
| 13 | 56920021347 |
| 14 | 371043659463 |
| 15 | 2412849114074 |
| 16 | 15655214564192 |
| 17 | 101363364976160 |
| 18 | 655024985471255 |
| 19 | 4225174990367555 |
| 20 | 27207648363845138 |