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 | 13 |
| 3 | 80 |
| 4 | 666 |
| 5 | 5080 |
| 6 | 40106 |
| 7 | 313136 |
| 8 | 2455013 |
| 9 | 19221095 |
| 10 | 150562121 |
| 11 | 1179185280 |
| 12 | 9235771513 |
| 13 | 72336253737 |
| 14 | 566554489205 |
| 15 | 4437377818704 |
| 16 | 34754532606346 |
| 17 | 272205182385544 |
| 18 | 2131971340412858 |
| 19 | 16698071766102576 |
| 20 | 130782997877002493 |