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 | 55 |
| 5 | 299 |
| 6 | 1900 |
| 7 | 13942 |
| 8 | 115932 |
| 9 | 1078361 |
| 10 | 11092265 |
| 11 | 125040100 |
| 12 | 1532995992 |
| 13 | 20310212672 |
| 14 | 289186696338 |
| 15 | 4404156016584 |
| 16 | 71441907922793 |
| 17 | 1229835421590959 |
| 18 | 22393298253477006 |
| 19 | 430019590699868644 |
| 20 | 8685717780508953928 |
| 21 | 184088653170341473400 |
| 22 | 4085097253151506682170 |