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 | 8 |
| 2 | 56 |
| 3 | 392 |
| 4 | 2696 |
| 5 | 18536 |
| 6 | 126536 |
| 7 | 863720 |
| 8 | 5873768 |
| 9 | 39942184 |
| 10 | 271009112 |
| 11 | 1838725896 |
| 12 | 12457092504 |
| 13 | 84392312392 |
| 14 | 571140732808 |
| 15 | 3865210690888 |
| 16 | 26138072412040 |
| 17 | 176752645426600 |
| 18 | 1194553221342296 |
| 19 | 8073068110703880 |
| 20 | 54534614510976680 |