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 | 13 |
| 2 | 73 |
| 3 | 337 |
| 4 | 1441 |
| 5 | 5953 |
| 6 | 24193 |
| 7 | 97537 |
| 8 | 391681 |
| 9 | 1569793 |
| 10 | 6285313 |
| 11 | 25153537 |
| 12 | 100638721 |
| 13 | 402604033 |
| 14 | 1610514433 |
| 15 | 6442254337 |
| 16 | 25769410561 |
| 17 | 103078428673 |
| 18 | 412315287553 |
| 19 | 1649264295937 |
| 20 | 6597063475201 |
| 21 | 26388266483713 |
| 22 | 105553091100673 |
| 23 | 422212414734337 |
| 24 | 1688849759600641 |
| 25 | 6755399239729153 |