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 | 0 |
| 2 | 0 |
| 3 | 8 |
| 4 | 54 |
| 5 | 228 |
| 6 | 708 |
| 7 | 1980 |
| 8 | 4890 |
| 9 | 11528 |
| 10 | 26004 |
| 11 | 57384 |
| 12 | 123786 |
| 13 | 265596 |
| 14 | 563664 |
| 15 | 1192220 |
| 16 | 2511474 |
| 17 | 5279208 |
| 18 | 11064216 |
| 19 | 23156448 |
| 20 | 48361110 |
| 21 | 100859180 |
| 22 | 209996772 |
| 23 | 436635396 |
| 24 | 906562842 |
| 25 | 1879950384 |
| 26 | 3893566872 |
| 27 | 8054935784 |
| 28 | 16645591974 |
| 29 | 34363631412 |
| 30 | 70872295524 |
| 31 | 146036933100 |