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 | 4 |
| 1 | 9 |
| 2 | 22 |
| 3 | 60 |
| 4 | 184 |
| 5 | 624 |
| 6 | 2272 |
| 7 | 8640 |
| 8 | 33664 |
| 9 | 132864 |
| 10 | 527872 |
| 11 | 2104320 |
| 12 | 8402944 |
| 13 | 33583104 |
| 14 | 134275072 |
| 15 | 536985600 |
| 16 | 2147713024 |
| 17 | 8590393344 |
| 18 | 34360655872 |
| 19 | 137440788480 |
| 20 | 549759483904 |
| 21 | 2199030595584 |
| 22 | 8796107702272 |
| 23 | 35184401448960 |
| 24 | 140737547075584 |
| 25 | 562950070861824 |
| 26 | 2251800048566272 |
| 27 | 9007199724503040 |