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 | 3 |
| 2 | 8 |
| 3 | 55 |
| 4 | 377 |
| 5 | 17711 |
| 6 | 121393 |
| 7 | 5702887 |
| 8 | 39088169 |
| 9 | 1836311903 |
| 10 | 591286729879 |
| 11 | 4052739537881 |
| 12 | 1304969544928657 |
| 13 | 61305790721611591 |
| 14 | 420196140727489673 |
| 15 | 19740274219868223167 |
| 16 | 6356306993006846248183 |
| 17 | 2046711111473984623691759 |
| 18 | 14028366653498915298923761 |
| 19 | 4517090495650391871408712937 |