The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 1 |
| 3 | 22 |
| 4 | 344 |
| 5 | 4671 |
| 6 | 59053 |
| 7 | 713985 |
| 8 | 8374417 |
| 9 | 96089849 |
| 10 | 1084355281 |
| 11 | 12078120713 |
| 12 | 133126886145 |
| 13 | 1454725651577 |
| 14 | 15781824417015 |
| 15 | 170163923182508 |
| 16 | 1825096021948551 |
| 17 | 19485528120720094 |
| 18 | 207200960219546637 |
| 19 | 2195466392318923180 |
| 20 | 23189231824423799723 |
[0,0,1,22,344,4671,59053,713985,8374417,96089849, 1084355281,12078120713,133126886145,1454725651577, 15781824417015,170163923182508,1825096021948551, 19485528120720094,207200960219546637, 2195466392318923180,23189231824423799723] |