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 | 3 |
| 3 | 12 |
| 4 | 61 |
| 5 | 370 |
| 6 | 2606 |
| 7 | 20925 |
| 8 | 188772 |
| 9 | 1890773 |
| 10 | 20822481 |
| 11 | 250082522 |
| 12 | 3253176309 |
| 13 | 45567394330 |
| 14 | 683783923476 |
| 15 | 10944068960451 |
| 16 | 186098265906832 |
| 17 | 3350501663825617 |
| 18 | 63671208559149815 |
| 19 | 1273621946395366224 |