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 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 8 |
| 5 | 18 |
| 6 | 40 |
| 7 | 101 |
| 8 | 254 |
| 9 | 723 |
| 10 | 2064 |
| 11 | 6586 |
| 12 | 21143 |
| 13 | 74752 |
| 14 | 266078 |
| 15 | 1029983 |
| 16 | 4013425 |
| 17 | 16843526 |
| 18 | 71136112 |
| 19 | 321150717 |
| 20 | 1458636308 |
| 21 | 7038678613 |
| 22 | 34161890155 |
| 23 | 175261038904 |
| 24 | 904125989974 |
| 25 | 4909033438008 |
| 26 | 26795600521492 |
| 27 | 153376337926066 |
| 28 | 882391616100249 |