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 | 1023 |
| 2 | 58025 |
| 3 | 989527 |
| 4 | 8717049 |
| 5 | 50700551 |
| 6 | 222009073 |
| 7 | 791266575 |
| 8 | 2413042577 |
| 9 | 6513215599 |
| 10 | 15937424601 |
| 11 | 35979939623 |
| 12 | 75941127625 |
| 13 | 151396163127 |
| 14 | 287395735649 |
| 15 | 522861237151 |
| 16 | 916482272673 |
| 17 | 1554473326175 |
| 18 | 2560599031177 |
| 19 | 4108933742199 |
| 20 | 6439880978201 |
| 21 | 9880041813223 |