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) |
|---|---|
| 1 | 1 |
| 2 | 12 |
| 3 | 75 |
| 4 | 384 |
| 5 | 1805 |
| 6 | 8100 |
| 7 | 35287 |
| 8 | 150528 |
| 9 | 632025 |
| 10 | 2620860 |
| 11 | 10759331 |
| 12 | 43804800 |
| 13 | 177105253 |
| 14 | 711809364 |
| 15 | 2846259375 |
| 16 | 11330543616 |
| 17 | 44929049777 |
| 18 | 177540878700 |
| 19 | 699402223099 |
| 20 | 2747583822720 |
| 21 | 10766828545725 |
| 22 | 42095796462852 |
| 23 | 164244726238343 |
| 24 | 639620518118400 |
| 25 | 2486558615814025 |