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 | 1 |
| 2 | 5 |
| 3 | 56 |
| 4 | 461 |
| 5 | 3558 |
| 6 | 23966 |
| 7 | 178127 |
| 8 | 1362597 |
| 9 | 10194184 |
| 10 | 75684682 |
| 11 | 561877016 |
| 12 | 4192125848 |
| 13 | 31292310312 |
| 14 | 233221376211 |
| 15 | 1737652233817 |
| 16 | 12950437458383 |
| 17 | 96538803978663 |
| 18 | 719609376905074 |
| 19 | 5363567352622148 |
| 20 | 39977107204818978 |
| 21 | 297975192242698825 |
| 22 | 2221015587432193750 |