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 | 6 |
| 2 | 20 |
| 3 | 56 |
| 4 | 145 |
| 5 | 362 |
| 6 | 888 |
| 7 | 2160 |
| 8 | 5233 |
| 9 | 12654 |
| 10 | 30572 |
| 11 | 73832 |
| 12 | 178273 |
| 13 | 430418 |
| 14 | 1039152 |
| 15 | 2508768 |
| 16 | 6056737 |
| 17 | 14622294 |
| 18 | 35301380 |
| 19 | 85225112 |
| 20 | 205751665 |
| 21 | 496728506 |
| 22 | 1199208744 |
| 23 | 2895146064 |
| 24 | 6989500945 |
| 25 | 16874148030 |
| 26 | 40737797084 |
| 27 | 98349742280 |
| 28 | 237437281729 |
| 29 | 573224305826 |
| 30 | 1383885893472 |