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 | 20 |
| 2 | 165 |
| 3 | 880 |
| 4 | 3575 |
| 5 | 12012 |
| 6 | 35035 |
| 7 | 91520 |
| 8 | 218790 |
| 9 | 486200 |
| 10 | 1016158 |
| 11 | 2015520 |
| 12 | 3821090 |
| 13 | 6963880 |
| 14 | 12257850 |
| 15 | 20920064 |
| 16 | 34730575 |
| 17 | 56241900 |
| 18 | 89049675 |
| 19 | 138138000 |
| 20 | 210315105 |
| 21 | 314757300 |
| 22 | 463681725 |
| 23 | 673171200 |
| 24 | 964177500 |
| 25 | 1363732656 |
| 26 | 1906401420 |
| 27 | 2636011840 |
| 28 | 3607704980 |