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 | 1 |
| 2 | 4 |
| 3 | 144 |
| 4 | 441 |
| 5 | 1444 |
| 6 | 10404 |
| 7 | 40401 |
| 8 | 1004004 |
| 9 | 1100401 |
| 10 | 4004001 |
| 11 | 100040004 |
| 12 | 114041041 |
| 13 | 400040001 |
| 14 | 414041104 |
| 15 | 10000400004 |
| 16 | 10110101401 |
| 17 | 40000400001 |
| 18 | 41011110144 |
| 19 | 141001001001 |
| 20 | 414441100441 |
| 21 | 1000004000004 |
| 22 | 1041110041104 |
| 23 | 4000004000001 |
| 24 | 4011400111104 |
| 25 | 100000040000004 |