A079752 Operation count to create all permutations of n distinct elements using the "streamlined" version of Algorithm L (lexicographic permutation generation) from Knuth's The Art of Computer Programming, Vol. 4, chapter 7.2.1.2. Sequence gives number of times the search for an element exchangeable with a_j has to be started.
0, 2, 13, 82, 579, 4638, 41749, 417498, 4592487, 55109854, 716428113, 10029993594, 150449903923, 2407198462782, 40922373867309, 736602729611578, 13995451862619999, 279909037252399998, 5878089782300399977
Offset: 3
Links
- Hugo Pfoertner, FORTRAN program for lexicographic permutation generation.
Programs
-
Mathematica
a[3] = 0; a[n_] := n*a[n - 1] + n - 2; Table[a[n], {n, 3, 21}]
Formula
a(3)=0, a(n) = n * a(n-1) + n - 2 for n>=4
Extensions
Edited and extended by Robert G. Wilson v, Jan 22 2003
Comments