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 | 5 |
| 3 | 21 |
| 4 | 92 |
| 5 | 414 |
| 6 | 1869 |
| 7 | 8427 |
| 8 | 37975 |
| 9 | 171121 |
| 10 | 771119 |
| 11 | 3474913 |
| 12 | 15659094 |
| 13 | 70564951 |
| 14 | 317988473 |
| 15 | 1432958824 |
| 16 | 6457375642 |
| 17 | 29099021980 |
| 18 | 131129599227 |
| 19 | 590912361256 |
| 20 | 2662842109828 |
| 21 | 11999627299824 |
| 22 | 54074199444301 |
| 23 | 243675821963849 |
| 24 | 1098082020999797 |
| 25 | 4948312537227216 |