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 | 2 |
| 3 | 7 |
| 4 | 74 |
| 5 | 543 |
| 6 | 10589 |
| 7 | 120009 |
| 8 | 3420257 |
| 9 | 4767631 |
| 10 | 2281311434 |
| 11 | 141441308909 |
| 12 | 51307141467 |
| 13 | 3301022547923 |
| 14 | 200573000466191 |
| 15 | 433638827007904943 |
| 16 | 328326540448842314 |
| 17 | 31534618884970203647 |
| 18 | 13785884222546140694347 |