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 | 1 |
| 3 | 0 |
| 4 | 1 |
| 5 | 0 |
| 6 | 1 |
| 7 | 3 |
| 8 | 7 |
| 9 | 14 |
| 10 | 43 |
| 11 | 115 |
| 12 | 326 |
| 13 | 931 |
| 14 | 2719 |
| 15 | 7979 |
| 16 | 23804 |
| 17 | 71418 |
| 18 | 216444 |
| 19 | 660276 |
| 20 | 2028558 |
| 21 | 6268350 |
| 22 | 19479746 |
| 23 | 60835542 |
| 24 | 190881085 |
| 25 | 601459251 |
| 26 | 1902680249 |
| 27 | 6040955223 |
| 28 | 19245061851 |
| 29 | 61503863732 |
| 30 | 197135868680 |
| 31 | 633615135842 |