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) |
|---|---|
| 2 | 1 |
| 3 | 2 |
| 4 | 3 |
| 5 | 7 |
| 6 | 17 |
| 7 | 1 |
| 8 | 19 |
| 9 | 167 |
| 10 | 1094 |
| 11 | 2899 |
| 12 | 1 |
| 13 | 13945 |
| 14 | 56817 |
| 15 | 155286 |
| 16 | 284489 |
| 17 | 785593 |
| 18 | 3268191 |
| 19 | 9099642 |
| 20 | 16950673 |
| 21 | 47515853 |
| 22 | 133587741 |
| 23 | 376586805 |
| 24 | 1064242599 |
| 25 | 1291914643 |
| 26 | 12834909238 |
| 27 | 36503886401 |
| 28 | 1944142787 |
| 29 | 19152993059 |
| 30 | 1144562017 |