| n | a(n) |
|---|---|
| 0 | 4 |
| 1 | 5 |
| 2 | 15 |
| 3 | 251 |
| 4 | 65523 |
| 5 | 4294967267 |
| 6 | 18446744073709551555 |
| 7 | 340282366920938463463374607431768211331 |
| 8 | 115792089237316195423570985008687907853269984665640564039457584007913129639683 |
[4,5,15,251,65523,4294967267,18446744073709551555, 340282366920938463463374607431768211331, 11579208923731619542357098500868790785326998466564\ 0564039457584007913129639683] |