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) |
|---|---|
| 3 | 1 |
| 4 | 13 |
| 5 | 71 |
| 6 | 396 |
| 7 | 1877 |
| 8 | 9199 |
| 9 | 47371 |
| 10 | 253108 |
| 11 | 1420475 |
| 12 | 8598976 |
| 13 | 55100124 |
| 14 | 369764734 |
| 15 | 2614650820 |
| 16 | 19473708445 |
| 17 | 151503397725 |
| 18 | 1226996194292 |
| 19 | 10339319950504 |
| 20 | 90530421514787 |
| 21 | 821670728202320 |
| 22 | 7714779905351852 |
| 23 | 74815825933883534 |
| 24 | 748526174347790448 |
| 25 | 7717807072187843156 |