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 | 5 |
| 4 | 33 |
| 5 | 141 |
| 6 | 492 |
| 7 | 1518 |
| 8 | 4320 |
| 9 | 11567 |
| 10 | 29601 |
| 11 | 72981 |
| 12 | 174652 |
| 13 | 407367 |
| 14 | 929859 |
| 15 | 2082284 |
| 16 | 4585752 |
| 17 | 9947997 |
| 18 | 21290967 |
| 19 | 45007311 |
| 20 | 94072878 |
| 21 | 194580977 |
| 22 | 398589723 |
| 23 | 809124321 |
| 24 | 1628620153 |
| 25 | 3252021750 |
| 26 | 6444843618 |
| 27 | 12681419489 |
| 28 | 24784331646 |
| 29 | 48126098418 |
| 30 | 92876836752 |