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 | 4 |
| 2 | 26 |
| 3 | 244 |
| 4 | 3131 |
| 5 | 52600 |
| 6 | 1111940 |
| 7 | 28559320 |
| 8 | 865622825 |
| 9 | 30250881420 |
| 10 | 1196941704454 |
| 11 | 52860066623036 |
| 12 | 2576115583371739 |
| 13 | 137274420821505776 |
| 14 | 7937914900025008984 |
| 15 | 494941882189888642832 |
| 16 | 33096552232229291234923 |