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 | 4 |
| 2 | 26 |
| 3 | 164 |
| 4 | 1031 |
| 5 | 6480 |
| 6 | 40728 |
| 7 | 255984 |
| 8 | 1608914 |
| 9 | 10112368 |
| 10 | 63558392 |
| 11 | 399478064 |
| 12 | 2510804924 |
| 13 | 15780945024 |
| 14 | 99186608832 |
| 15 | 623409013632 |
| 16 | 3918258753416 |
| 17 | 24627092844352 |
| 18 | 154786536605216 |
| 19 | 972866430709568 |
| 20 | 6114673231661936 |
| 21 | 38432026791933696 |
| 22 | 241553493927992448 |