The number of permutations of the first n elements of the Hofstaedter Q-sequence (A005185), augmented by Q(0)=1.
A169637
The number of permutations of the first n elements of the Hofstaedter Q-sequence (A005185), augmented by Q(0)=1.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =4a(4) =20a(5) =60a(6) =420a(7) =3360a(8) =15120a(9) =151200a(10) =831600a(11) =3326400a(12) =43243200a(13) =302702400a(14) =1513512000a(15) =24216192000a(16) =411675264000
External references
- oeis: A169637