The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | -3 |
| 4 | 43 |
| 5 | -95 |
| 6 | 12139 |
| 7 | -25333 |
| 8 | 81227 |
| 9 | -498233 |
| 10 | 121563469 |
| 11 | -246183839 |
| 12 | 32808117961 |
| 13 | -13219717433 |
| 14 | 3226018634857 |
| 15 | -8835766426243 |
| 16 | 390013167515221 |
| 17 | -260612031438103 |
| 18 | 36514732926665911 |
| 19 | -73104960503491573 |
| 20 | 9265088297941326563 |
| 21 | -389193444786378151123 |
[0,1,-3,43,-95,12139,-25333,81227,-498233, 121563469,-246183839,32808117961,-13219717433, 3226018634857,-8835766426243,390013167515221, -260612031438103,36514732926665911, -73104960503491573,9265088297941326563, -389193444786378151123] |