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) |
|---|---|
| 1 | 1 |
| 2 | 6 |
| 3 | 28 |
| 4 | 133 |
| 5 | 651 |
| 6 | 3206 |
| 7 | 15771 |
| 8 | 77519 |
| 9 | 380989 |
| 10 | 1872556 |
| 11 | 9203761 |
| 12 | 45237262 |
| 13 | 222344668 |
| 14 | 1092840924 |
| 15 | 5371396171 |
| 16 | 26400821252 |
| 17 | 129762048116 |
| 18 | 637790353236 |
| 19 | 3134788177277 |
| 20 | 15407722718291 |
| 21 | 75730131016730 |
| 22 | 372219363549007 |
| 23 | 1829486529878612 |
| 24 | 8992065676243395 |