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 | 5 |
| 2 | 16 |
| 3 | 78 |
| 4 | 274 |
| 5 | 1132 |
| 6 | 4468 |
| 7 | 17742 |
| 8 | 70616 |
| 9 | 281202 |
| 10 | 1117442 |
| 11 | 4448148 |
| 12 | 17693664 |
| 13 | 70390082 |
| 14 | 280040518 |
| 15 | 1114106280 |
| 16 | 4432207738 |
| 17 | 17633023628 |
| 18 | 70149839190 |
| 19 | 279079644000 |
| 20 | 1110273409628 |
| 21 | 4417041071578 |
| 22 | 17572471614384 |
| 23 | 69909222737482 |