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 | 5 |
| 2 | 30 |
| 3 | 110 |
| 4 | 365 |
| 5 | 1001 |
| 6 | 2520 |
| 7 | 5720 |
| 8 | 12190 |
| 9 | 24310 |
| 10 | 46252 |
| 11 | 83980 |
| 12 | 147070 |
| 13 | 248710 |
| 14 | 408760 |
| 15 | 653752 |
| 16 | 1021735 |
| 17 | 1562275 |
| 18 | 2343770 |
| 19 | 3453450 |
| 20 | 5008003 |
| 21 | 7153575 |
| 22 | 10080720 |
| 23 | 14024400 |
| 24 | 19284460 |
| 25 | 26225628 |
| 26 | 35304920 |
| 27 | 47071640 |