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 | 5 |
| 2 | 33 |
| 3 | 281 |
| 4 | 2993 |
| 5 | 38705 |
| 6 | 592489 |
| 7 | 10516441 |
| 8 | 212841889 |
| 9 | 4845154913 |
| 10 | 122664558905 |
| 11 | 3421333467689 |
| 12 | 104297273041969 |
| 13 | 3451364116327249 |
| 14 | 123251578626936841 |
| 15 | 4725537745859375705 |
| 16 | 193647372258547916609 |
| 17 | 8447809104669814884545 |
| 18 | 390938955429073736493145 |