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 | 28 |
| 3 | 244 |
| 4 | 2396 |
| 5 | 25324 |
| 6 | 281140 |
| 7 | 3232352 |
| 8 | 38151196 |
| 9 | 459594316 |
| 10 | 5628197948 |
| 11 | 69859456440 |
| 12 | 876985904276 |
| 13 | 11115789165888 |
| 14 | 142066687799680 |
| 15 | 1828884017527504 |
| 16 | 23694360858872604 |
| 17 | 308714491495346028 |
| 18 | 4042605442981407388 |
| 19 | 53178663502737007352 |