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 | 3 |
| 3 | 6 |
| 4 | 27 |
| 5 | 276 |
| 6 | 1755 |
| 7 | 24865 |
| 8 | 646029 |
| 9 | 7946521 |
| 10 | 195711271 |
| 11 | 4129119136 |
| 12 | 198635909763 |
| 13 | 6351380968517 |
| 14 | 322641218722443 |
| 15 | 11068897188590241 |
| 16 | 501741852481602261 |
| 17 | 24367382928343066431 |
| 18 | 1292304206793356882286 |