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 | 0 |
| 3 | 1 |
| 4 | 4 |
| 5 | 14 |
| 6 | 47 |
| 7 | 155 |
| 8 | 508 |
| 9 | 1662 |
| 10 | 5438 |
| 11 | 17809 |
| 12 | 58395 |
| 13 | 191732 |
| 14 | 630373 |
| 15 | 2075221 |
| 16 | 6840140 |
| 17 | 22571800 |
| 18 | 74564874 |
| 19 | 246568051 |
| 20 | 816099650 |
| 21 | 2703492238 |
| 22 | 8963064935 |
| 23 | 29738123605 |
| 24 | 98735734915 |
| 25 | 328034119098 |
| 26 | 1090509180192 |
| 27 | 3627343273885 |
| 28 | 12072071392105 |
| 29 | 40197107361740 |
| 30 | 133910579452363 |