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) |
|---|---|
| 4 | 1 |
| 5 | 17 |
| 6 | 131 |
| 7 | 709 |
| 8 | 3350 |
| 9 | 14337 |
| 10 | 57507 |
| 11 | 218746 |
| 12 | 803384 |
| 13 | 2870707 |
| 14 | 10044838 |
| 15 | 34548917 |
| 16 | 117224825 |
| 17 | 393290329 |
| 18 | 1307200931 |
| 19 | 4310348599 |
| 20 | 14116544717 |
| 21 | 45959805027 |
| 22 | 148860350902 |
| 23 | 479938536114 |
| 24 | 1541025955958 |
| 25 | 4929773150983 |