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 | 4 |
| 3 | 19 |
| 4 | 80 |
| 5 | 391 |
| 6 | 1738 |
| 7 | 8797 |
| 8 | 40878 |
| 9 | 212491 |
| 10 | 1023392 |
| 11 | 5426518 |
| 12 | 26891674 |
| 13 | 144717381 |
| 14 | 733600690 |
| 15 | 3991767587 |
| 16 | 20603079346 |
| 17 | 113049604075 |
| 18 | 591971513924 |
| 19 | 3269119157724 |
| 20 | 17319091807608 |
| 21 | 96127613360983 |
| 22 | 514139933872914 |
| 23 | 2865265217457906 |
| 24 | 15446276427044382 |
| 25 | 86367699910234830 |