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) |
|---|---|
| 3 | 1 |
| 4 | 9 |
| 5 | 47 |
| 6 | 188 |
| 7 | 643 |
| 8 | 1993 |
| 9 | 5798 |
| 10 | 16193 |
| 11 | 44068 |
| 12 | 118013 |
| 13 | 312974 |
| 14 | 825277 |
| 15 | 2169045 |
| 16 | 5690426 |
| 17 | 14913861 |
| 18 | 39066661 |
| 19 | 102306471 |
| 20 | 267879086 |
| 21 | 701364436 |
| 22 | 1836256726 |
| 23 | 4807458872 |
| 24 | 12586185670 |
| 25 | 32951178868 |
| 26 | 86267449214 |
| 27 | 225851287529 |