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) |
|---|---|
| 2 | 1 |
| 3 | 5 |
| 4 | 21 |
| 5 | 88 |
| 6 | 387 |
| 7 | 1816 |
| 8 | 9123 |
| 9 | 48971 |
| 10 | 279855 |
| 11 | 1695902 |
| 12 | 10856879 |
| 13 | 73173016 |
| 14 | 517597981 |
| 15 | 3831970709 |
| 16 | 29617983433 |
| 17 | 238460465120 |
| 18 | 1995828043987 |
| 19 | 17333096360920 |
| 20 | 155936489571399 |
| 21 | 1451019052068763 |
| 22 | 13945778132786915 |
| 23 | 138259832617525950 |
| 24 | 1412263078623261399 |