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 | 15 |
| 2 | 210 |
| 3 | 3285 |
| 4 | 59395 |
| 5 | 1241270 |
| 6 | 29720808 |
| 7 | 806720492 |
| 8 | 24568601477 |
| 9 | 831697990069 |
| 10 | 31036137984664 |
| 11 | 1267376997249262 |
| 12 | 56270606942915489 |
| 13 | 2701018385881136958 |
| 14 | 139463341982980040911 |
| 15 | 7711492696761363573725 |