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 | 3 |
| 2 | 30 |
| 3 | 105 |
| 4 | 210 |
| 5 | 231 |
| 6 | 30030 |
| 7 | 2145 |
| 8 | 72930 |
| 9 | 969969 |
| 10 | 9699690 |
| 11 | 10140585 |
| 12 | 20281170 |
| 13 | 22287 |
| 14 | 6463230 |
| 15 | 7713865005 |
| 16 | 15427730010 |
| 17 | 90751353 |
| 18 | 436514007930 |
| 19 | 1641030105 |
| 20 | 134564468610 |
| 21 | 368217318651 |
| 22 | 3682173186510 |
| 23 | 3762220429695 |
| 24 | 127915494609630 |
| 25 | 1546231253523 |
| 26 | 819502564367190 |
| 27 | 54496920530418135 |