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 | 12 |
| 1 | 20 |
| 2 | 44 |
| 3 | 122 |
| 4 | 392 |
| 5 | 1370 |
| 6 | 5024 |
| 7 | 18962 |
| 8 | 72872 |
| 9 | 283370 |
| 10 | 1110704 |
| 11 | 4377602 |
| 12 | 17320952 |
| 13 | 68727770 |
| 14 | 273267584 |
| 15 | 1088189042 |
| 16 | 4338210632 |
| 17 | 17309402570 |
| 18 | 69107683664 |
| 19 | 276041741282 |
| 20 | 1103001557912 |
| 21 | 4408513155770 |
| 22 | 17623579686944 |
| 23 | 70462912522322 |
| 24 | 281757456578792 |