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 | 3400 |
| 2 | 20175 |
| 3 | 180983 |
| 4 | 549151 |
| 5 | 1952201 |
| 6 | 4267249 |
| 7 | 10332299 |
| 8 | 29423591 |
| 9 | 55576643 |
| 10 | 118484257 |
| 11 | 213829309 |
| 12 | 332208601 |
| 13 | 492209651 |
| 14 | 794548943 |
| 15 | 1362464799 |
| 16 | 1977716093 |
| 17 | 2909645707 |
| 18 | 3998950759 |
| 19 | 5227426051 |
| 20 | 6954357343 |
| 21 | 9089168635 |