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 | 8 |
| 2 | 28 |
| 3 | 80 |
| 4 | 340 |
| 5 | 2872 |
| 6 | 23272 |
| 7 | 150496 |
| 8 | 878032 |
| 9 | 5590352 |
| 10 | 40944964 |
| 11 | 308188080 |
| 12 | 2214574160 |
| 13 | 15460447160 |
| 14 | 109979357264 |
| 15 | 810265214336 |
| 16 | 6054587741784 |
| 17 | 44971580074120 |
| 18 | 332187742343988 |
| 19 | 2466464253968144 |
| 20 | 18500526368526048 |
| 21 | 139644462606436800 |
| 22 | 1055241582609777512 |
| 23 | 7976465101937086048 |