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 | 19 |
| 3 | 121 |
| 4 | 771 |
| 5 | 4913 |
| 6 | 31307 |
| 7 | 199497 |
| 8 | 1271251 |
| 9 | 8100769 |
| 10 | 51620379 |
| 11 | 328939577 |
| 12 | 2096095523 |
| 13 | 13356910353 |
| 14 | 85113990379 |
| 15 | 542370291241 |
| 16 | 3456136077171 |
| 17 | 22023471375233 |
| 18 | 140339755317947 |
| 19 | 894284401724697 |
| 20 | 5698631790801091 |
| 21 | 36313284928708849 |
| 22 | 231398467337757579 |