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 | 7 |
| 3 | 27 |
| 4 | 121 |
| 5 | 483 |
| 6 | 1751 |
| 7 | 5694 |
| 8 | 16870 |
| 9 | 46014 |
| 10 | 116842 |
| 11 | 278837 |
| 12 | 630353 |
| 13 | 1358517 |
| 14 | 2806843 |
| 15 | 5584567 |
| 16 | 10741640 |
| 17 | 20039166 |
| 18 | 36362252 |
| 19 | 64333159 |
| 20 | 111214759 |
| 21 | 188207532 |
| 22 | 312302096 |
| 23 | 508868575 |
| 24 | 815256003 |
| 25 | 1285706310 |
| 26 | 1998034336 |
| 27 | 3062559792 |