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 | 10 |
| 2 | 72 |
| 3 | 538 |
| 4 | 4176 |
| 5 | 33010 |
| 6 | 262872 |
| 7 | 2099338 |
| 8 | 16783776 |
| 9 | 134237410 |
| 10 | 1073800872 |
| 11 | 8590111738 |
| 12 | 68720008176 |
| 13 | 549757408210 |
| 14 | 4398051294072 |
| 15 | 35184386437738 |
| 16 | 281475019757376 |
| 17 | 2251799942825410 |
| 18 | 18014398896902472 |
| 19 | 144115189238117338 |