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 | 5 |
| 3 | 22 |
| 4 | 125 |
| 5 | 746 |
| 6 | 5677 |
| 7 | 44780 |
| 8 | 420401 |
| 9 | 4206970 |
| 10 | 47543141 |
| 11 | 562891352 |
| 12 | 7573655905 |
| 13 | 104684547566 |
| 14 | 1596368400005 |
| 15 | 25482043382476 |
| 16 | 439969180782017 |
| 17 | 7835163501390290 |
| 18 | 151712475696833221 |
| 19 | 3004182138648663200 |
| 20 | 63854641556089628801 |
| 21 | 1400563708969910620822 |