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 | 0 |
| 2 | 1 |
| 3 | 7 |
| 4 | 31 |
| 5 | 114 |
| 6 | 385 |
| 7 | 1250 |
| 8 | 3987 |
| 9 | 12619 |
| 10 | 39810 |
| 11 | 125425 |
| 12 | 394955 |
| 13 | 1243433 |
| 14 | 3914383 |
| 15 | 12322293 |
| 16 | 38789576 |
| 17 | 122105944 |
| 18 | 384377494 |
| 19 | 1209981891 |
| 20 | 3808901216 |
| 21 | 11990036895 |
| 22 | 37743426054 |
| 23 | 118812495000 |
| 24 | 374009739009 |
| 25 | 1177344897390 |
| 26 | 3706162867858 |
| 27 | 11666626518622 |
| 28 | 36725362368682 |
| 29 | 115607732787126 |
| 30 | 363921470561515 |