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) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 17 |
| 3 | 68 |
| 4 | 242 |
| 5 | 812 |
| 6 | 2619 |
| 7 | 8224 |
| 8 | 25345 |
| 9 | 77006 |
| 10 | 231355 |
| 11 | 688758 |
| 12 | 2034965 |
| 13 | 5973932 |
| 14 | 17441201 |
| 15 | 50678536 |
| 16 | 146643235 |
| 17 | 422769139 |
| 18 | 1214857227 |
| 19 | 3480786068 |
| 20 | 9946872233 |
| 21 | 28357093263 |
| 22 | 80667175724 |
| 23 | 229020154166 |
| 24 | 649028530125 |
| 25 | 1836242560272 |
| 26 | 5187142333288 |
| 27 | 14632132586005 |