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 | 1 |
| 2 | 7 |
| 3 | 127 |
| 4 | 4377 |
| 5 | 245481 |
| 6 | 20391523 |
| 7 | 2354116899 |
| 8 | 360734454993 |
| 9 | 70865037282673 |
| 10 | 17367953099244051 |
| 11 | 5195706189463681299 |
| 12 | 1863485648739527246569 |
| 13 | 789370246456579516316121 |
| 14 | 389929989984983783920348611 |
| 15 | 222178771969671609391720410691 |
| 16 | 144648509476124539709343154760897 |
| 17 | 106712830948451223242311469280356609 |
| 18 | 88557950557114913966623605248882438755 |
| 19 | 82132537612235618834557329353828430430755 |