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 | 1 |
| 1 | 13 |
| 2 | 123 |
| 3 | 1037 |
| 4 | 8291 |
| 5 | 64509 |
| 6 | 494595 |
| 7 | 3761661 |
| 8 | 28486659 |
| 9 | 215277565 |
| 10 | 1625688067 |
| 11 | 12277764093 |
| 12 | 92783468547 |
| 13 | 701828038653 |
| 14 | 5314762113027 |
| 15 | 40297495658493 |
| 16 | 305941006516227 |
| 17 | 2325794003091453 |
| 18 | 17704219384479747 |