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 | 12 |
| 2 | 132 |
| 3 | 1396 |
| 4 | 14436 |
| 5 | 147120 |
| 6 | 1483996 |
| 7 | 14854968 |
| 8 | 147821604 |
| 9 | 1464031120 |
| 10 | 14443875984 |
| 11 | 142042418004 |
| 12 | 1393053544508 |
| 13 | 13630170286224 |
| 14 | 133092301736232 |
| 15 | 1297274743175856 |
| 16 | 12624909478998948 |
| 17 | 122692158505386960 |
| 18 | 1190859983017752880 |
| 19 | 11545524234978791952 |
| 20 | 111820579340839270416 |