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 | 6 |
| 2 | 36 |
| 3 | 90 |
| 4 | 225 |
| 5 | 825 |
| 6 | 3025 |
| 7 | 9240 |
| 8 | 28224 |
| 9 | 93912 |
| 10 | 312481 |
| 11 | 997815 |
| 12 | 3186225 |
| 13 | 10377990 |
| 14 | 33802596 |
| 15 | 109041570 |
| 16 | 351750025 |
| 17 | 1140060185 |
| 18 | 3695059369 |
| 19 | 11948292720 |
| 20 | 38635833600 |
| 21 | 125075648880 |
| 22 | 404906960329 |
| 23 | 1310059883431 |
| 24 | 4238645087209 |