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 | 2 |
| 3 | 6 |
| 4 | 24 |
| 5 | 119 |
| 6 | 708 |
| 7 | 4914 |
| 8 | 38977 |
| 9 | 347793 |
| 10 | 3448182 |
| 11 | 37605545 |
| 12 | 447406214 |
| 13 | 5766525727 |
| 14 | 80040747361 |
| 15 | 1190340631290 |
| 16 | 18882526564227 |
| 17 | 318256944873984 |
| 18 | 5679619717431613 |
| 19 | 106989639176572571 |
| 20 | 2121488012937187849 |
| 21 | 44170136425049025574 |
| 22 | 963430265253564585315 |