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 | 3 |
| 4 | 11 |
| 5 | 40 |
| 6 | 148 |
| 7 | 553 |
| 8 | 2083 |
| 9 | 7896 |
| 10 | 30086 |
| 11 | 115126 |
| 12 | 442118 |
| 13 | 1703052 |
| 14 | 6577474 |
| 15 | 25461493 |
| 16 | 98759971 |
| 17 | 383751472 |
| 18 | 1493506534 |
| 19 | 5820778858 |
| 20 | 22714926826 |
| 21 | 88745372992 |
| 22 | 347087585824 |
| 23 | 1358789148058 |
| 24 | 5324148664846 |
| 25 | 20878676356240 |
| 26 | 81937643449468 |
| 27 | 321786401450268 |