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 | 4 |
| 3 | 91 |
| 4 | 240 |
| 5 | 840 |
| 6 | 989 |
| 7 | 5396 |
| 8 | 117719 |
| 9 | 312120 |
| 10 | 1089720 |
| 11 | 1284121 |
| 12 | 7003804 |
| 13 | 152799571 |
| 14 | 405130920 |
| 15 | 1414456320 |
| 16 | 1666787669 |
| 17 | 9090932396 |
| 18 | 198333725039 |
| 19 | 525859622640 |
| 20 | 1835963213040 |
| 21 | 2163489110641 |
| 22 | 11800023246004 |
| 23 | 257437022301451 |