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 | 5 |
| 4 | 15 |
| 5 | 54 |
| 6 | 227 |
| 7 | 1085 |
| 8 | 5774 |
| 9 | 33679 |
| 10 | 212807 |
| 11 | 1443622 |
| 12 | 10439565 |
| 13 | 80016693 |
| 14 | 646976322 |
| 15 | 5496339141 |
| 16 | 48894262619 |
| 17 | 454113866430 |
| 18 | 4392175247939 |
| 19 | 44138842357617 |
| 20 | 459956754593094 |
| 21 | 4961220069886511 |
| 22 | 55301147935270395 |
| 23 | 636091223462294518 |
| 24 | 7539926971001192381 |