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 | 3 |
| 3 | 16 |
| 4 | 121 |
| 5 | 1191 |
| 6 | 14461 |
| 7 | 209098 |
| 8 | 3510921 |
| 9 | 67175461 |
| 10 | 1443249271 |
| 11 | 34412298636 |
| 12 | 901898694313 |
| 13 | 25775139581491 |
| 14 | 797824620178041 |
| 15 | 26592701386533766 |
| 16 | 949705032131053201 |
| 17 | 36181186751341438473 |
| 18 | 1464760631695118359051 |
| 19 | 62798619981256526628136 |