A178010 Number of permutations of 1..n with no element e[i>=2]

1, 1, 1, 2, 6, 24, 120, 360, 1680, 10080, 72576, 604800, 3326400, 26611200, 259459200, 2905943040, 36324288000, 290594304000, 3293402112000, 44460928512000, 675806113382400, 11263435223040000, 118266069841920000, 1734569024348160000, 29921315670005760000

Offset: 0

Author

R. H. Hardin, May 17 2010

Keywords

• nonn

Links

• Alois P. Heinz, Table of n, a(n) for n = 0..484
• Wikipedia, D-ary heap

Crossrefs

Simple 2-way heap A056971.

Column k=5 of A273693.

Extensions

a(0), a(21)-a(24) from Alois P. Heinz, May 27 2016