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 | 1 |
| 3 | 6 |
| 4 | 31 |
| 5 | 186 |
| 6 | 1191 |
| 7 | 7972 |
| 8 | 55164 |
| 9 | 391322 |
| 10 | 2830751 |
| 11 | 20801826 |
| 12 | 154853413 |
| 13 | 1165316224 |
| 14 | 8850372878 |
| 15 | 67750780816 |
| 16 | 522218420336 |
| 17 | 4049564739054 |
| 18 | 31570368061361 |
| 19 | 247293510244174 |
| 20 | 1945331619223591 |
| 21 | 15361731119713506 |
| 22 | 121729460653957980 |
| 23 | 967664450692965300 |