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 | 26 |
| 4 | 130 |
| 5 | 651 |
| 6 | 3255 |
| 7 | 16276 |
| 8 | 81380 |
| 9 | 406901 |
| 10 | 2034505 |
| 11 | 10172526 |
| 12 | 50862630 |
| 13 | 254313151 |
| 14 | 1271565755 |
| 15 | 6357828776 |
| 16 | 31789143880 |
| 17 | 158945719401 |
| 18 | 794728597005 |
| 19 | 3973642985026 |
| 20 | 19868214925130 |
| 21 | 99341074625651 |
| 22 | 496705373128255 |