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 | 7 |
| 2 | 26 |
| 3 | 156 |
| 4 | 692 |
| 5 | 3580 |
| 6 | 17742 |
| 7 | 88056 |
| 8 | 439338 |
| 9 | 2192602 |
| 10 | 10912392 |
| 11 | 54394628 |
| 12 | 271160024 |
| 13 | 1351103246 |
| 14 | 6733077562 |
| 15 | 33557756016 |
| 16 | 167232569172 |
| 17 | 833404135538 |
| 18 | 4153405692526 |
| 19 | 20698773896328 |
| 20 | 103153449929238 |
| 21 | 514074952403758 |