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 | 60 |
| 5 | 315 |
| 6 | 1869 |
| 7 | 11472 |
| 8 | 74797 |
| 9 | 502908 |
| 10 | 3505031 |
| 11 | 24973089 |
| 12 | 182208083 |
| 13 | 1352620790 |
| 14 | 10207771213 |
| 15 | 78082422354 |
| 16 | 604699597868 |
| 17 | 4733082767467 |
| 18 | 37406134058641 |
| 19 | 298165102770381 |
| 20 | 2395219866441531 |
| 21 | 19376637845028027 |
| 22 | 157757577529194488 |
| 23 | 1291926016200778464 |