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) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 3 |
| 4 | 9 |
| 5 | 34 |
| 6 | 176 |
| 7 | 1106 |
| 8 | 8241 |
| 9 | 70371 |
| 10 | 676098 |
| 11 | 7204713 |
| 12 | 84252233 |
| 13 | 1072010712 |
| 14 | 14738107136 |
| 15 | 217656602456 |
| 16 | 3435793029849 |
| 17 | 57721548509705 |
| 18 | 1028183730411650 |
| 19 | 19354550056977555 |
| 20 | 383876766917923073 |
| 21 | 8001053425278668706 |
| 22 | 174828593537337033648 |
| 23 | 3996207024319062050994 |