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 | 2 |
| 3 | 3 |
| 4 | 6 |
| 5 | 12 |
| 6 | 31 |
| 7 | 89 |
| 8 | 303 |
| 9 | 1119 |
| 10 | 4649 |
| 11 | 20572 |
| 12 | 99241 |
| 13 | 502622 |
| 14 | 2725840 |
| 15 | 15424019 |
| 16 | 92211327 |
| 17 | 571446565 |
| 18 | 3716191974 |
| 19 | 24920512847 |
| 20 | 174169990243 |
| 21 | 1251875604302 |
| 22 | 9326245177768 |
| 23 | 71241318920624 |
| 24 | 562221733320241 |
| 25 | 4535497053407716 |
| 26 | 37677863148632647 |
| 27 | 319551379756283637 |